WHO 2008
Upcoming SlideShare
Loading in...5

Like this? Share it with your network


WHO 2008



WHO Classification of tumors of hematologic and lymphoid tissue 2008 (4th Ed)

WHO Classification of tumors of hematologic and lymphoid tissue 2008 (4th Ed)



Total Views
Views on SlideShare
Embed Views



0 Embeds 0

No embeds


Upload Details

Uploaded via as Adobe PDF

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
Post Comment
Edit your comment

WHO 2008 Document Transcript

  • 1. World Health Orga nization Classifica tion of Tumours Hamilton SR. Aartonen LA (Eds.) : Fletcher C.D.. Unni KK., Tavassoli F A .. Devilee P. (Eds .): World Health Organization Mertens F. (Eds,): World Health World Health Organization Classification of Tumours , Organization Classification 01 Classification 01 Tumours . Patholog y and Genetics of Tumours Tumours. Patho logy and Genetics 01 Pathology and Genetics of Tumours of the Digestive System (3rd edition) . Tumours of Soft Tissue and Bone of the Breast and Female Genital IARC Press: lyon 2000 (3rd edition). Organs (3rd edition). ISBN 92 832 241 0 8 IARC Press : lyon 2002 IARC Press : lyon 2003 ISBN 92 832 2413 2 ISBN 92 832 2412 4 Eble J .N., Sauter G .• Epstein J E., Travis wo., Brambilla E., Muller· Delellis A.A., lloyd A.V, Heitz, P.U., Sesterreon l.A . (Eds.) World Health Hermelink H.K ., Harris C .C. (Eds.): Eng C . (Eds.): World Hea lth Organization Classification of World Health Organization Organization Classification of Tumours. Pathology and Genetics of Classification 01 Tumours. Pathology TlJTlOUrs. Pathology and Genetics ot Tumours althe Urinary System and and Genetics of Tumours of lung TlJTlOUrs of Endocrine Organs (3rd Male Genital Organs (Jrd ed ition) P1eu"a. Thyrrus and Heart (3I"d edilon), edition). fARe Press : lyon 2004 IARC Press : lyon 2004 IARC Press : lyon 2004 ISBN 92 832 2415 9 ISBN 92 832 2418 3 ISBN 92 832 2416 7 Barnes L , Eveson J .W , Reichart P" leBoit P.E.. Burg G , Weedon D., louis D.N" Ohgaki H ., WiesUer D.O., Sidransky 0 (Eds.): World Health Sarasm A . (Ed s.): World Health Cavenee WK (Ed s.) : World Health Organization Classification of Organization Classification of Organization Classification of Tumours. Pathology and Genetics of Tumours. Pathology and Genetics of Tumours . Tumours of the Central Head and Neck Tumours (3I"d edition) . Skin Tumou rs (3rd edition). Nervous System (4th edition ). IARC Press : lyon 2005 IA RC Press : lyon 2006 IARC, lyon 2007 ISBN 92 832 24 17 5 ISBN 92 832 2414 0 ISBN 92 832 2430 2This book and all other volumes of the series can be purchased from: From all countries WHO PRESS World Health Organization 20 Avenu e Appia 1211 Geneva 27 Switzer land www. who intlbookord ers/ Tei. + 4 1 22 791 3264 Fax +41 22 791 4857 bcokoroersewno.ot From USA I Canada WHO Publications Center 5 San d Creek Road Albany, NY 1205- 1400 Tel. +15184369686 Fax . + 1518436 7433 qcorpeconouserve.com Renouf Pub lishing Co. lid http://www.renoufbooks.comJ From USA : Tel.+18885517470 Fax +18885517471 From Canada: Tel. + 1 866 767 6766 Fax +16137457660
  • 2. -.I
  • 3. •I WH O OMS International Agency for Research on Cancer (IARC) 4th Edition WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues Edited by Steven H. Swe rdlow Elias Campo Nancy Lee Harris Elaine S. Jaffe Stefano A. Pileri Harald Stein JOrgen Thiele James W. Vardiman Intern ational Agency for Resea rch on Cancer Lyon , 2008
  • 4. World Health Organization Classification of Tumours Series Editors Fred T. Bosman, M.D. Elaine S. Jaffe. M.D. Sunil R. Lakhani. M.D. Hiroko Onqaki, Ph.D.WHO Classification of Tumours of the Haematopoietic and Lymphoid Tissues Editors Sleven H. Swerdlow, M.D. Elias Campo. M.D. Nancy Lee Harris, M.D. Elaine S. Jaffe , M D. Stefano A. Pileri. M.D. Harald Stein, M.D. JOrg en Thiele, M.D. James W. Vardi man, M.D. Layout Sebastien Antoni Marlen Grassinger Pascale Collard Printed by Participe Present 69250 Neuville s/SaOne, France Publisher International Agency for Research on Cance r (IARC) 69008 Lyon. France
  • 5. • This volume was produced with support from the Associazione S.P.E.S. Onlus, Bologna Friends of Jose Carreras International Leukemia Foundation Leukemia Clinical Research Foundation MEDIC Foundation National Cancer Institute, USA National Institutes of Health Office of Rare Diseases, USA University of Chicago Cancer Research Center The WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues presented in this book reflects the views of a Working Group that convened for an Editorial and Consensus Conference at the International Agency for Research on Cancer (fARC), Lyon October 25-27. 2007. Members of the Working Grou p are indicated in the List of Contributors on pages 369-374.
  • 6. Published by the International Agenc y for Research 00 Cancer (IARC), 150 cou rs Albert Thomas, 69372 Lyon ceoex 08, France C International Agency for Research on Cancer, 2008 Distributed by WHO Press, World Health Organization , 20 Avenue Appia, 1211 Geneva 27, Switzerland (Tel: +4 1 22 791 3264; Fax: +4 1 22 791 4857; e-mail: bookordersOwholnt). PubliCations Of the World Health Organization enjoy copyright crotectco in accordance with the proviecos of Protocol 2 of the Universal Copyright Coeventoo. All rights reserved . The designatiOns employed and the presentation ot the material in this publicatiOn do not imply the expression ot any opiniOn whatsoever on the part of the secretarial 01 the WOOd Health OrganiZatiOn concerning the legal status 01 any country , territory. city . or area or 01 its authonltes , or concerning the delimitatiOn 01 its frontiers or ccooca-ee. The mootion ol scecac companies or 01 certain manufacturers products does not imply that they are encIorned or fecorrmellded by the World Health Organization in preference to others of a smilar nature that are not mentioned Errors and omissions excepted, the rwnes 01 proprietary products are distmguished by initial capnatjetters. The authors alone are responsible fOf the views expressed in this pubhcatlQfl. The copyright of figures and charts remains with the authors (see source 01 charts and photographs. page 376--379)Format for bibliographic citations:Swerdlow S.H., Campo E., Harris N,L., Jaffe E.S" Pileri S.A., Stein H" Thiele J , Vardiman J.w. (Eds.):WHO Classification of Tumours of Haematopoietic and Lympho id Tissues,IARC: Lyon 2008IARC Ubrary Cataloguing in Publication DataWHO Classific ation of Tumou rs of Haematopo ietic and Lymp hoid TissuesEdited by Swerdlow S.H.. Campo E., Harris NL , Jaffe E.S.• Piled SA, Stein H., Thiele J .. Vardiman JW.1. Haematopoie hc System Neop lasms - genetics2. Haematopoielic System Neop lasms - pathologyI. Swerdlow. Steven H.ISBN 978-92-832-243 1-0
  • 7. ContentsWHO Classifjcatioo 9 AML with mutated NPM 1 120 Summary table 10 AMLwith mutated CEBPA 122 Introduction to the classification of tumours of AML with myelo dysplas ia-related changes 124 haematopoietic and lymphoid tissues 14 Therapy -relate d myeloid neoplasms 127 Acu te myeloid leukaemia, NOS 130 Introduction and overview of the classification of AML with minimal diff erentiation 130 the myeloid neoplasms 17 AML withOut matu ration 131 AML with maturabon 1312 Myeloproliferative neoplasms 31 Acute myelomonocytic leukae mia 132 Chronic myelogenous leukaemia. BCR-ABL 1 positive 32 Acute monoblastic and monocytic leukaem ia 133 Chronic neutrophilic leukaemia 38 Acute erythroid leukaemia 134 PoIycythaemia vera 40 Acu te megakaryoblastic leukaemia 136 Primary myelofibrOsis 44 Acute basophilic leukaemia 137 Essenliallhrombocythaemia 48 Acu te paomveosrs with myelofibros is 138 Chronic eosinophilic leukaemia. NOS 51 Myeloid sarcoma 140 Mastocytosis 54 Myeloid proli ferations related 10 Down synd rome 142 Cutaneous mastocytosis 57 Transient abnOrmal myelopoiesis 142 Systemic mastocytosis 58 Myeloid leukaemia associated with Masl cell leukaemia 61 Dc:rwn syndrome 143 Mast cell sarcoma 61 Blastic plasmacytoid dendritic cell neoplasm 145 Extracutaneous mastocytoma 61 Myeloproliferative neoplasm, unc lassi fiable 64 7 Acute leukaemiasof ambiguous lineage 149 Acute undlHerentiated leukaemia 1513 Myeloid and lymphoid neoplasms with Mixed phenotype acute leukaemia wilh eosinophilia and abnormalities of PDGFRA. t(9;22)(q34;q 11.2): BCR-ABL 1 15 1 PDGFRB Of FGFRl 67 Mixed phenotype acute leukaemia with t(v:11q 23): MLL rear ranged 1524 MyelodysplasticJmyeloproliferative neoplasms 75 Mixed phenotype acute leukaemia , B/myeloid, NOS 152 Chronic mveiomonocync leukaemia 76 Mixed phenotype ac ute leukaemia , T/myeloid , NOS 153 Atypical ctYonic myeloid leukaEmia. BCR- ABL 1 negative 80 Mixed phenoty pe acu te leukaemia, NOS· rare Juvenile myelomonocytic leuk aemia 82 types 154 MyelodysplastiC/myeloproliferali ve neoplasm , Other ambiguous lineage reukaerraes t 55 urclasaifiable 85 Natura! killer (NK)-celilympho blastic leukaemi a/lymphoma 1555 Myelodysplastic syndromes 87 Myelodysplastic synd romes/n eo plasms , overview 88 8 Introduction and overview 01 the c lassification of Refractory cytope nia with unilineage dysplasia 94 the lymphoid neoplasms 157 Refractory anaemia with ring side rob lasts 96 Refractory cytopenia with multilineage dysplasia 98 9 Precu rsor lymphoid neoplasms 167 Refractory anaemia with exc ess b lasts 100 B lymp hob lastic leukaemia/lymphoma, NOS 168 Myelodysp lastic synd rome with isolated de l(5q) 102 B lymphob lastic leukaemia/ lymphoma Myelodysp lastic synd rome, uncrasslttabte 103 with recu rrent gene tic abn orma lities 171 Childhood mye lodysp lastic synd rome 104 B lymphob lastic leukaem iallymphoma with Refractory c ytopenia of c hild hood 104 t(9 :22)(q 34;q 11.2): BCR-ABL 1 171 B lymp hoblastic leukaemia/ly mpho ma with6 Acute myeloid leukaemia (AML) and l(v:11q 23): ML L rearranged 171 related precursor neoplasms 109 B lympho blastic leukaemiall ymphom a with AML with recurrent genet ic abn or malities 11 0 t(12:2 1)(p1 3;q22 ): TEL-AMLl (ETV6--RUNX 1) 172 AML with t(8:21 )(q22:q22); RUNX1 -RUNX1T1 11 0 B lymphoblastic leukaemia/lymphoma with AML with inv( 16)( p 13.1q22) or hyperdi ploi dy 173 1(16:t6)(p 13.1;q22): CBFB-MYH 11 11 1 B lymphoblastic leukaemiallymphom a with Acute orornveiocvnc leukaem ia with hypodiplOi dy (Hypodiploi d ALL) 174 t(15:17)(q22 :q 12): PML- RARA 11 2 B lymphoblastic leukaemiallymphoma with AML with us.11)(p 22:q 23): MLLT3-MLL 114 t(5; 14)(q31;q32); IL3-IGH 174 AML with t(6:9)(p23 :q34); DEK-NU P2 14 115 B lymphoblastic leukaemiallymphoma with AML with inv(3)( q2 1q26 .2) or t(3;3)( q2 1;q26.2); t( 1;19) (q23:P13.3): E2A-PBX1( TCF3-PBXI) 175 RPNt ·EVI1 116 T lymphoblastic leukaemiallymphoma 176 AML (megakaryoblastic) with t( 1;22)(p13;q 13): RBM15-MKL 1 117
  • 8. 10 Mature B-ceUneoplasms 179 Enteropathy -associated t-een lymphoma 289 Chronic lymphocytic leukaemia Ismail Hepatosplenlc t -een lymphoma 292 Iymptlocytic lymphoma :f 180 Subcutaneous panniculitis-like t-een lymphoma 294 s-een prolyrT¢lhocytic leukaemia 183 Mycosis fungoi des 296 Splenic B-cell marginal zone lymphoma 185 Sezary syndrome 299 Hairy cell leukaemia 188 Primary cutaneous CD30 posi tive t-een Splenic B-cell Iymphomalleukaemia, unclassiliable 191 Iymphoprolilerative disorders 300 Splenic diffuse red pulp small B-ceil lymphoma 191 Primary cutaneous per ipheral t-een lymphoma s, Hairy cenleckaeme-....anent 192 rare subtypes 302 lymphoplasmacytic lymphoma 194 Primary cutaneous garnna-della T-cen lymphoma 302 Heavy chain diseases 196 Primary cutaneous COB positive agg ressive Gamma heavy chain disease 196 ep idermotrop ic cytotoxic T-celt lymphoma 303 Mu heavy chain disease 197 Primary cutaneou s CD4 positive Alpha heavy chain disease 198 small/medium T-cell lymphoma 304 Plasma cell neoplasms 200 Peripheral t-een lymphoma. NOS 306 Monoc lonal gammop athy 01 undetermined Ang ioimmunoblastic t -een lymphoma 309 significance (MGUS) 200 Anaplastic large cell lymphoma. AlK positive 312 Plasma ce ll myeloma 202 Anapla stic large cell lymphoma . ALK negat ive 317 Solitary plasmacytoma of bone 208 Extraosseous plasmacytoma 208 12 Hod gkin lymphoma 32 1 Monoclonal immunoglobulin deposition diseases 209 Introduction 322 Extranodat marginal zone lymphoma of mucosa- Nodular lymphocyte predominant Hodgkin Iymptuna 323 associa ted lymphoid tissue (MALT lymphoma) 214 Classical Hodgk in lymp homa. introduction 326 Nodal marg inal zone lymphoma 218 Nodular sclerosis classical Hodgkin lymphoma 330 Follicular lymphoma 220 Mixed ce llularity classical Hodgkin lymphoma 331 Primary cutaneous follicle centre lymphoma 227 Lymphoc yte-rich classical Hodgkin lymphoma 332 Mantle cell lymphoma 229 lymphocyte-depleted classical Hodgkin lymphoma 334 Diffuse large B-celllymphoma (DLBCl), NOS 233 T celilhi stiocyte-rich large B-ce ll lymphoma 238 13 1rnmunode ficiency-assoc iated Primary DlBCL of the CNS 240 Iymphoproliferative disorde rs 335 Primary cutaneous DlBCl . leg type 242 Lymp hoproliferative diseases associated with EBV positive DLBCl of the elderly 243 primary immune disorders 336 DLBCL assoc iated with chronic inflammation 245 Lymphomas associa ted with HIV infection 340 Lymphomatoid granulomatosis 247 Post-nansotanttsmpnooronterauve disorders (PTlD) 343 Primary med iastinal (thymic) large B-celilymphoma 250 Plasmacytic hyperp lasia and infectious- Intrav escurer large B-celi lymphoma 252 rroooo ocieose-uke PTlD 345 ALK positive large Been lymphoma 254 Polymorphic PTlO 346 Plasmablastic lymphoma 256 Monomorph ic PTlO 347 large a-ceu lymphoma arising in HHV8-associated Classical Hodgkin lymphoma type PTLO 349 multicent ric Castleman disease 258 Other iatrogenic immunodeficiency-assoc iated Primary effusion lymphoma 260 Iymphoproliferative disorders 350 Burkitllymp homa 262 B-cel1lymphoma, unclassiliab le, with features 14 Histiocytic and dendritic cell neoplasms 353 intermediate between DLBCL and Introd uction 354 Burkitllymphoma 265 Histiocyt ic sarcoma 3S6 B-ceillymphoma, unctessmebie. with features Tumours der ived from langerhans cells 358 intermediate between OLBCl and Langerhans cell histiocytosis 3S8 clas sica l Hodgkin lymphoma 267 Langerhans ce ll sarcoma 360 Interdigitating dendrit ic cell sarcoma 36 1 11 Mature T- and NK-cell neoplasms 269 Follicular de ndritic ce ll sarcoma 363 r-cea prolymphocytic leukaemia 270 Other rare dendritic cell tumours 365 t- een large granular lymphocytic leukaemia 272 Disseminated juvenile xanthogranuloma 366 Chronic Iymphoproliferative disorder of NK cells 274 Aggressive NK cell leukaemia 276 Contributors 369 Epstein-Barr virus (EBV) positive t-een Clinical advi sory oorrrnittee 374 Iymphoprol ilerative diseases of ch ildhood 278 Source of Charts and photographs 376 Systemic EBV+ t-een Iymphoproliferalive disease of childhood 278 References 300 Hydroa vacclnrtorrne-uk e lymphoma 280 Subject index 429 Adull T-ceil leukaemia/lymphoma 281 Extranodal NK/T-cell lymphoma. nasal type 285 NOS, no! otherwise specifi ed,•
  • 9. WHO Classification 4th Edition- / / -.,.e" / , ...,...,... ~ /,f / - ~ ~~ - -~ ~ _....i? ~.,.~-
  • 10. WHO Classification of tumours of haematopoieticand lymphoid tissues MYELOPROLIFERATIVE NEOPLASMS MYELODYSPLASTIC SYNDROMES Chronic myelogenous leukaemia , Refractory cytopenia with unilineage dysplasia BCR-ABL 1 positive 987513 Refractory anaemia 9980/3 Chronic neutrophilic leukaemia 996 3/3 Refractory neutropenia 999 1/3 Polycythaemia vera 995 0/3 Refractory thrombocytopenia 9992/3 Primary myelofibrosis 996 1/3 Refractory anaemia with ring sideroblasts 9962/3 Essential thrombocythaemia 996213 Refractory cytopenia with Chronic eosinophilic leukaemia, NOS 9964 /3 multitineage dysplasia 9965/3 Mastocytosis Refractory anaemia with excess blasts 9983/3 Cutaneous mastocytosis 9 74011 MyelodysplasU syndrome c associated with isolated del(Sq) 9966/3 Systemic mastocytosis 9 74 1/3 Myelodysplasticsyndrome, uncJassifiable 9969/3 Mast cell leukaemia 974 213 Mast cell sarcoma 974 0/3 Childhood myelodyspla suc syndrome Extracutaneous mastocytoma 974 0/1 Refractory cytopenia of childhood 996513 Myeloproliferative neoplasm , unctassitlable 9975/3 ACUTE MYELOID LEUKAEMIA (AML) AND RELATED PRECURSOR NEOPLASMS MYELOID AND LYMPHOID NEOPLASMS WITH EOSINOPHILIA AND ABNORMALITIES OF AML with recurr ent genetic abnormalities PDGFRA, PDGFRB OR FGFRI AML with t(6 ;21)(q22;q2 2); Myeloid and lymphoid neoplasms RUNXI-RUNX1Tl 9696/3 with PD GFRA rearrangement 9965/3 AML with inv(16)(pI 3.1q22 ) Myeloid neoplasms or t(16;16)(pI3.1;q2 2); CBFB-MYHl1 9671/3 with PDGFRB rearrangement 9966/3 Acute promyelccytlc leukaemia Myeloid and lymphoid neoplasms with t(15 ;17)(q22 ;qI2); PML-RARA 9666/3 with FGFR1 abnormalities 9967/3 AML with t(9 ;11)(p22 ;q23); MLLT3-MLL 9697/3 AML with 1(6;9)(p2 3;q34 ); DEK-NUP214 986513 MYELODYSPLASTIC/MYELOPROLIFERAnVE AML with inv( 3)(q2 1q26.2) NEOPLASMS ort(3; 3)(q21;q 26.2); RPNI -EV/1 9869/3 Chronic myetcmonocytic leukaemia 9945/3 AML (megakaryoblastic) with t(I ;22)(p I 3;q I 3); RBMI5-MKLI 9911/3 Atypical chronic myeloid leukaemia. BCR-ABL 1 negative 967613 AML with mutated NPM1 986 1/3 Juvenile myelomonocytic leukaemia 9946/3 AML wrlh mutated CEBPA 9661/3 Myelodysplasticlmyeloproliferative neoplasm. unclassifiable 9975/3 AML with myelodysplasia-related changes 969513 Refractory anaemia with ring sideroblasts Therapy-re lated myeloid neoplasm s 99 2013 associated WI h marked thrombocyt t osis 99 621310 WHO ctassrtceton
  • 11. Acute myeloid leukaemla",NOS 9861/3 B lymphoblastic leukaemia/lymphoma with recurrent genetic abnormalities AML with minimal differentiation 987213 B lymphoblastic leukaemiaflymphoma AML without maturation 9873/3 with 1(9;22)(q 34;q l 1.2); BCR-ABU 9812/3 AML with maturation 9874 /3 B lymphoblastic leukaemiall ymphoma Acute myelomonocytic leukaemia 9867 /3 with t(v;11q23); MLL rearranged 981Y3 Acute monob lastic and monocytic leukaemia 9891 /3 B lymphoblastic leukaemiall ymphoma Acute erythroid leukaemia 984013 with 1 12;21)(p13;q22); TEL-AMU ( (ETV6-RUNX1) 9814/3 Acute megakaryoblastic leukaemia 99 10/3 B lymphoblastic leukaemiallymphoma Acute basoph ilic leukaemia 987013 w ith hyperdiploidy 981513 Acute panmyelosis with myelofibrosis 9931 13 B lymphoblastic leukaemiallymphoma with hypod iploidy (hypod iploid ALL) 981613Myeloid sarcoma 993013 B lymphoblastic leukaemiallymphoma with t(5;14 Xq31 ;q32 ); IL3-IGH 9817/3 B lymphoblastic leukaemia/lymphoma withMyeloid proliferations related to Down syndrome t(1;19 )(q23 ;p13 .3); E2A-PBXlTransient abnormal myelopoiesis 989811 (TCF3-PBX1) 9818/3Myeloid leukaemia associated with Down syndrome 9898/3 T lymphoblastic leukaemia/lymphoma 9837/3Blastic plasmacytoid dendritic cell neoplasm 9727/3 MATURE B-CELL NEOPLASMS Chronic lym phocytic leukaemia! small lymphocytic lymphoma 982313ACUTE LEUKAEMIAS OF AMBIGUOUS LINEAGE B-cell prolymphocytic leukaemia 983313Acute undifferentiated leukaemia 980 1/3 Splenic Bccell marginal zone lymphoma 968913Mixed phenotype ac ute leukaemia Hairy cell leukaemia 9940/3 with t(9;22)(q3 4;q 11.2); BCR-ABL1 980613Mixed phenotype ac ute leuka em ia Splenic B-cell fymphomalleukaemia, unclassifiable 959 1/3 with t{v;11q23); MLL rea rranged 9807/3 Splenic diffuse red pulp small B-cell lymphoma 9591/3Mixed phenotype ac ute leukaemia, Hairy eel/leukaemia-variant 959 1/3 B/myeloid, NO S 9808/3 Lymphoplasmacytic lymphoma 9671/3Mixed phenotype ac ute leukaemia, Tfmyeloid, NOS 9809/3 waldenstrom macroglobulinemia 9761/3Natural killer (NK) cell lymphoblastic Heavy chain diseases 9762/3 !euKaemiallymphoma Alpha heavy chain disease 9762/3 Gamma heavy chain disease 9762/3 Mu heavy cha in disease 9762/3PRECURSOR LYMPHOID NEOPLASMS Plasma cell myeloma 9732/3B lymphoblastic leukaemiaflymphoma Solitary plasmacytoma of bone 9731/3B lymphoblastic leukaemiall ymphoma, NO S 98 11/3 Extraosseous plasmacytoma 9734/3 WHO classification 11
  • 12. - Extranodal marginal zone lymphoma Systemic EBV positive T-celllymphoproliferative of mucosa-associated lymphoid tissue disease of childhood 9724/3 (MALT lymphoma) 9699/3 Hydroa vaccin iforme-like lymp homa 972513 Nodal marginal zone lymphom a 9699/3 Adult T-cell ieukaemia/lymphoma 9827/3 Paediatric nodal marginal zone lymphoma 9699/3 Extranodal NKIT cell lym phoma, nasal type 9719 /3 Follicular lymphoma 9690/3 Enteropamy-associated T-cell lymphoma 9717/3 Paediatric folliculaf lymphoma 9690/3 Hepatosplenic T-cell lymp homa 971613 Primary cutaneous follicle centre lym phoma 959713 Subcutaneous panniculitis-like T-cell lymphoma 970813 Mantle cell lymphoma 967313 Mycosis fungoides 970013 Diffuse large B-eelllymphoma (OlBCl), NOS 968013 Sezary syndrome 970113 T-ceillhistiocyte rich large B-eelilymphorna 9688/3 Primary cutaneous CD30 positive F-eel! Primary DLBCl of the CNS 968013 Iymphoproliferative disorders Primary cutaneous DlBCl. leg type 9680/3 9718/1 lymphomatoid papulosis EBV positive OLBCL of the elderly 9680/3 Primary cutaneous anaplastic large cell Ol BCl associated with chro nic inflammation 968013 lymphoma 9718/3 l ymphomatoid granulomatosis 9766 /1 Primary cutaneous qamma-delta r -ceuivmpncma 9726/3 Primary med iastinal (thym ic) large B-celllym phoma 9679/3 Primary cutaneous COB positive aggressive epidermotropic cytotoxic T-cefl lymphoma 9709/3 Intravascular large B-cell lymphoma 971213 Primary cutaneous CD4 positive smalVmedium AlK positive large B-cell lym phoma 9737/3 T-cell lymphoma 9709/3 Plasmablastic lymphoma 973 5/3 Peripheral Tccelllympboma, NOS 970213 l arge Bccell lymp homa arising in HHV8- Angioimmunoblastic l-cetl Iyrnphoma 970513 associated multicentric Castleman disease 9738/3 Anaplastic large cell lymp homa, ALK positive 97 14/3 Primary effusio n lymphoma 9678/3 968 7/3 Anaplastic large cell lymphoma, ALK negative 970213 Burkitt lymph oma B-ceillym phom a, uncl assifiable, with feature s intermediate between diffuse large g-ceu lymph oma and Burkitt lymph oma 968 0/3 HODGKIN LYMPHOMA B-ceil lymph oma , unclassifiable, with feat ures Nodular lymphocyte predomi nant intermediate betwee n diffuse large 8-cell 9659/3 Hodgkin lymp homa lymphoma and classica l Hodgkin lymphoma 9596/3 Classical Hodgkin lymp homa 9650/3 Nodular sclerosis classical Hodgkin lymphoma 9663/3 MATURE T-CELL AND NK·CELL NEOPLASMS l ymphocyte-rich classica l j-cen prolymphocytic leukaemia 9834/3 Hodgkin lymphoma 965113 f-celllarqe granular lym phocytic leukaemi a 983 1/3 Mixed cellularity classica lI Chronic Iymphoproliferative disorder of NK..cells 983113 Hodgkin lymphoma l ymphocyte-depleted classical 965213~l.. Aggressive NK cell leukaemia 9948/3 Hodgkin lymphoma 965313 12 WHO ciassitcenon _
  • 13. HISTIOCYTIC AND DENDRITIC CELL NEOPLASMSHistiocytic sarcoma 9755 /3l angerhans cell histiocytosis 975 1/3langerhans cell sarcoma 9756/3Interdigitating dendritic cell sarcoma 9757/3Follicular dendritic cell sarcoma 975813Fibroblastic reticu lar cell tumour 9759/3Indeterminate dendritic cell tumour 9757/3Disseminated juvenile xanthogranulomaPOST·TRANS PLANT LYMPHOPROUFERATIVEDISORDERS (PTLO)Early lesi ons P1asmacytic hyperplasia 9971/1 Infectious mononucleosis-like PTLD 9971 /1Polymorphic PTLO 9971/3Monomorphic PTlO (B- and TINK-cell types)Classical Hodgkin lym phoma type PTLO"NOS, not otherwise speci fied .The italicized numbers are provi siona l cod es for the 4thedition of lCD -D . While they are expected to be incorpo-rated in the next ICD -O editi on , they currentty remainsubjectto changes.The italicized histologi c type s are provisional enti ties , forwhich the WHO Working Group fe ll the re was insufficientevidence to recognize as distinct diseases at this time."These lesions are classi fied according to the leukaemia orlymphoma to which they correspond, and are assigned therespective tCO-G code. WHO classification 13
  • 14. Introduction to the WHO classification NL Harris E. Campo H. Stein S.H. Swerdlow of tumours of-haernatopoletlc E.S. Jaffe SA Pileri J Thiele J w. Vardiman and lymphoid tissues Why classify? Classification is the lan- committees was incorporated into the classification , involvement of clinicians is guage of medic ine: diseases must be class ification. Over 130 pa thologists and essential to ensure its usefulness and ac- described , defin ed and named before the y haem ato logis ts from around the world ceptance in daily practice 18971. At the lime can be diagnosed , treated and stud ied . were involved in writing the chap ters. A of publication of the WHO classi fication A consensus on definition s and termin ol- consensus meeting was held at the head - (3rd edition), prop onents of other cla ssifi- og y is essent ial for both clinic al practice quarters of the IARC in Lyon, France. to cations of haematologic neoplasms agreed and investigation . A cl assification should make final d eci sions on the classi ficatio n to use the new cl assification, thus ending contain diseases thai are clearly defin ed . and the con tent of the book. decad es of cont roversy over the classifi- c linically d istinc tive . norKlVerlappi ng (mu- cation of these tumo urs 147. 478 . t 89. tually excllsive) and that together comprise The WHO cl assification of tumours of the 1B9A, 190, 673,7750 , 1344A. 18198 1 , all known entities (collectively e xha ustive). haematopoietic an d lymphoid system is II should serve as a ba sis lor future inves- based on the principles initially d efined in As indicated above , there is no one -gold tigation . and should be able to incorporate the "Revised Europe an-Amer ican Classi- stand ard ," by which all diseases are new information as it becomes ava ilab le. fica tion of Lymp hoid Neoplasms" (REAL). def ined in the WHO cl assific ation. Mor- Classification has two aspects: clas s dis- from the Interna tiona l Lymphoma Stud y pholog y is alway s important, and many covery - the proces s of identifying cate- Group (ILSG) 18981. In the WHO classifi- diseases have ch aracteristic or even di- gories of diseases, and class pre diction cation, these p rinciples have also been agnosti c morphologic featu res, Immune- - the process of determining which cere- appl ied to the class ification of myeloid phe notype and genetic features are an gory an individual case belongs to. Pamer- and his tiocy tic neoplasms, The gu id ing important part of the definition of tumours ogi sts are critical to both processes . prin cip le of the REAL and WHO cl assifi- of the naematopolettc and lymphoid c ations is the attempt to define "real" tissues , and the av ailability of this infor- The World Hea lth Org anizati on (WHO) d iseases that c an be recognized by mation makes arriving at conse nsus defi- Classi fication of Tumours of the Haema- pa tholo gi sts with availabl e techniques. nitions easier now than it was when only topoietic and Lymp hOid Tissues (4th Edi- and that appear be distinct clinical enti- subjec tive morphologic criteria were tion ) was a coll aborative project of the ties . There are 3 important com ponents to available . lrrmunophenotyping studies are European Association for Haematopathol- this p rocess First. recognizing tha t the used in routine diagnosis in the vast ogy and the Society lor Hematopatholog y. underlying c auses of these neo plasms majority of haematolog ic mali gn ancies, It is a revision and update of the 3rd Edi- are often unknown and may vary, this ap- both to d etermine lineage in malig nant tion 11039 }. which was the first true proa ch to cl assifica tion uses all available processes and to dis tinguish be nig n lrom worldwide consensus c lassific ation of information - morpholog y, immunop he- ma lignant processes . Many disea ses baematoiocic malignancies. The update, notype, genetic features, and cl inical fea- have a chara ct eristic immunophenotype. which began in 2006, had an a-me mbe r tures- to define diseases. The relative such that one would hesitate to make the steering committee composed of membe rs impo rtance of eac h of these features diagnosis in the abse nce of the immune- of both societies, The Steering Comminee, varies among diseases, d epend ing upon p henot yp e, while in others the immuno- in a series of meetings and discussions, the state of current knowledge, and there onenotvpe is only part of the diagnosis, In agreed on a proposed list of diseases is therefore no one "g old standard ," by some lymphoi d and in many myeloid ne0- and chapters and selec ted authors. with which all di seases are defined . Second. p lasms a speci fic genetic abnorma lity is input from both soc ieties. As with the rec ognizing that the com plexity 01 the the key defining criterion, while etters lack WHO 3fd ed ition 1 71. the advice of clin - 89 field makes it impossib le for a single specific known genet ic ebnomantes. ical haematologists and oncologists was expert Of small g roup to be comptet ely Some g enetic abnormalities, while char- obtained . in order to ensure that the clas- authoritative, and that broad agreement is acteri stic of one dis ea se, are not specific sifica tion will be clinica lly useful. Two Clin- necessary if a classificati on is to be ac - (such as MYC. CCND 1or BCl2 rearrange- ic al Adv isory Committee s (CAG). one for cep ted, this cta ssrncanon relies on bu ild - ments or mutations in JAK2). and others myeloid neoplasm s and other acut e ing a consensus among as many experts are prognostic factors in several diseases leukaemias and one for lym phoid neo- as possible on the def inition and nomen- (such as TP mutations or FLT3-ITO) , 53 plasms. were convened, The mee tings clatu re of the diseases, We recognize that The inc lusion of jr munoohenotvoc lea- were org anized aroun d a ser ies of com promise is essential in orde r to arrive tures and genetic abnormalities to define questions, inc luding disease definitions, at a consensus, but bel ieve that the only entities not only provides ob jective criteria nomenclature, grading. and clinical rele- thing worse than an imperfect classifica- for disease recogni tion but has identified vance. The committ ees were able to tion is multiple competing classifi cati ons . antigens, genes or pathways that can be reach consensus on mos t of the ques- Finally. wh ile patholog ists must take targeted for therapy; the success of tions po sed . and muc h of the inp ut of the pr imary respon sib ility for developing a rituxima b , an anti-CD20 molecule, in the 14 Introduction to the classification.. .
  • 15. treatment of. B-cel! neoplasms, and 01 ord er of listing is in part arb itrary, and is the WHO classification has produced aimatinib in the treatment of leukaemias as- not an integral part of the cl assification. new and exciting degree of cooperationsociated with ABL 1 and oth re!lrrange- and conmunic ation among patholog istsments inv olving tryoene kinase genes are The 4th ed ition of the WHO classification and oncologists from around the world .testament to this approach. Finally. some inc orpo rates new information that has which stould facilitate con tinued progressdiseases require know ledge of clinical emerged from basic and clinic al in....estr- in the understand ing and treatment offeatures - age, nodal versus extranodal gat ions in the interva l since pu b lication of haema totog ic manqnaocies . The mullipa-presentan on. specific anatomic site . and the 3rd edition . It inc ludes new defining rameter approach to c lassification, withhistory 01 cytotoxic and other therapies criter ia for some disease s, as well as a an emphasis on defining real disease- to make the diagnosis. Most 01 the dis- number of new entities. some def ined by entites. tha t has be en ad opted by theeases described in the WHO classification genetic criteria - particul arly among the WHO classification, has been shown inare considered to be distinct enti ties ; myeloid neoplasm s- and others by a inte rnational studi es 10 be reproducible:howev er. some are not as clearly defined, combination of morpholog y. immunoph e- the disea ses d efined are c linically dis-and these are listed as prov isional entities, ootype . and clinic al features. The frequent ttnct iv e. and the uniform definitions andIn addition . borderline categories ha....e application of immunophenotyping and terminology facilitate the interpretation ofbeen created in this edition for cases that genetic stud ies to peripheral blood, bone clinical and translational stud ies 1 1, 791 . 5do not c learly fit into one category, so that ma rrow, and lym ph node samp les has In addition, accurate and precise classifi -well-de fined categories ca n be kept also led to the de tection of small clonal c ation of d isease entities has facilitatedhomogeneous, and the borderline cases populations in asy mptomatic pe rsons . the discovery of the genetic bas is ofcan be stud ied further. These include small clones of cells with the my eloid and lymphoid neoplasms in the BCR-ABL 1 translocation seen in chronic ba sic science laboratoryThe WHO classification stratifiesneoplasms myelogenous leukaemia. small cl ones ofprimarily ac cording to lineag e: myeloid, ce lls with BCL2-IGH rearrangement. andlymphoid, and histiocyticfdendritic c ell. A small populat ions of c ells that have thenormal c ounterpart is postulaled lor each imm uoopheootype of chronic lymp hocyticneoplasm. While the goal is to define the leukaemia (e l l ) or folli cu lar lymphomalineag e of each neoplasm, lineage pla s- (mo noc lonal B lymphocytosis, follicularticity may occur in precursor or imma ture lymphoma-in Situ , paediatric follicul ar hy-neoplasms, and has recently been identi- perplas ia WIth monoclonal B c ells). Infied in some mature haematotymphoid man y case s. it is not clear whether theseneoplasms , In addition, genetic atooe - represent earty involvement by a neoplasm,rreuues suc h as FGFR1, PDGFA and a precursor iesoo. or an inconsequentialPDGFB rearrangements may give rise to find ing. These situations have someneoplasms 01 either myel oid or lymphoid ana logies to the identification of smalllineage associated with eosinophilia ; monoclonal immunoglobulin componentsthese disorders are now recognized as a in serum (monoclonal gammopathy ofseparate group. Precursor neoplasms unknown significance), The ch apters on(acute myeloid reukaemes. lymphoblastic these neoplasms include recommenda-Iymphomasfleukaemias, acute reukaerraas tions for dea ling with these situations. The01 amb iguo us lineag e, and blast ic p las- rec omm end ations of international con -macytoid de nd ritic ce ll neop lasm ) are sens us group s have bee n co nsidered.considered separately from mo re mature with regard to criteria for the d iagnosis ofneoplasms [myeloproliferative neoplasms e ll, plasma cell myeloma, Waldenstr6m(MPN). myelodysplastic/myeloproliterative macroglobulinemia, and new subtypes ofneoplasms, myelodysplastic syndromes , cutaneous lymphomas, as well as in themature (peripheral) B-cell and T/NK -cell development of new algorithms for the neoplasms, Hodgkin lymphoma. and his- diagnosis of MPN .Iiocyteldeodritic-c ell neoplasms] . The ma- ture myeloid neoplasms are stratified A critic al feature of any class ification of according to the ir bi ologica l features diseases is that it be periodically reviewed (myeIoploIiferative, with effective baereio- and updated to incorpor ate new informa- poiesis. ....ersus myelodysplastic , with in- tion. TheSocietyfor Haematopathology and effective neematcootesfs . as welt a s by the European Association for Haemato- genetiC feature s). Within the mature lym- pathology now have a more than to-year phoid neop lasms , the diseases are listed record of couebceaton and coo pe ration in broadly ac cord ing to clinical presentation this effort. The societies are comm itted to (disseminated often leukaemi c, extran - updating and revising the classification coat. indolent. aggressiv e). and to some as needed . with input lrom clinicians and extent according to stage of differentiation with the collaboration of the WHO . The when this can be postulated: howe....er the experience of developing and updating Introdu ction to the cl assification 15
  • 16. • ) CHAPTER 1 Introduction and Overview of the Classification of the Myeloid Neoplasms •-, "
  • 17. Introduction and overview of the J.w. Vardiman A.D. Brunning A. Porwit A . retten classification of the myeloid neoplasms D.A . Arter M.M.Le Beau C.D. Bloomfield J. Thiele The WHO Classification of Tumours of the by its c linic al and morphologic features, genetic features is used in an anerrctt c Haematopoietic and Lymphoid Tissue s and its natural progression is charac ter- define d isease entities , such as CML, that (3rd edition) published in 200 1 reflected ized by an inc rease in blasts of myeloid , are biolog ically homogeneous and clini- a pa radigm shift in the approach to c las- lymphoid or m ixed myeloid/lymphoid cally relevant - the same approach used sification of myeloid neoplasms { 1039). For immunop henotype. It is always associ- in the 3rd ed ition of the classification. the first time. genetic information was in- ated with the BCR·ABL 1 fusion gen e that Altho ugh the previous scheme began to cor porated into diagnostic algorithms results in the production 01 an abnormal open the door to including genetic ab- provided lor the vario us en tities. The pub- protein tyros ine kinase (PTK) with en- normalities as c riteria to classi fy myeloid licat ion was prefac ed with a comment hance d enzyma tic ac tivity. This p rotein is neoplasms, this rev ision firmly acknow l- pred icti ng future revisions nec essitated sut tcrentto ca use the leukaem ia and also edges that as in CML, recu rring ge netic by rapidly eme rg ing gen el ic information. provides a targ et for prote in tyrosi ne abno rmali ties provi de not onl y objec tive The cu rrent revision is a commentary on kinase inhibi tor (PTKI) the ra py tha t has c rite ria for recognition of speci fic entities the significant ne w molecular insights mat prolonge d the lives of thousands of pa - but also identification of abnormal gene have bec ome avail abl e since the publi- tients with this often tatal illness {6 151. product s or pathways that are potent ial cation of the last ctassncauon . This successful integ ratio n of cl inical , targets for therapy. One example in this The first entity described in this mono- morphologi c and genetic information em- revised sc heme is the addition of a new graph . chronic myelogenous leukaemia bodies the goal of the WHO classific ation subgroup of mye loid neoplasm s (Tabte (CML) rema ins the prototype for the iden- scheme. 1.01) assoc iated with eos inoph ilia and tification and c lassific atio n of myeloid In th is revis ion . a combination of c linica l, chromo somal ab normalities that involve neoplasms This leukaemia is recognized morpholog ic . imm uno phe noty pic and the oiateiet-oenved growth factor rece ptor .- Table 1.01 Themyeloid neoplasms major sul:9OUJlS and dal;U::i tstic features at ~ .........., .... """" - -- 0..... 8M ctllularity 10 MIrfOW bluts HatrnatopOitsit MPN Usually increased. En-. VanabIe; 008 or Co<m>oo often normalin ET tbmaJ or sIighlIy increased: <10% in dIonic phase """" G••,,,, relabYe/y normal, """..- IifIeage usually """""""", """""" irullallyincreased MyeIoidIIymphoid Increased Normal or $IigM~ Present Relatively normal Elfectrve Eosinophilia Com~ neoplasmswith increased: <20% irl j~t 5x10ir1.) eosinophilia and abriof· cnronc phase malilies of PDGFRA. PDGFRB Of FGFRI MOS Nom1al or incr eased: Preserlt ~lasia inoreor Inel!&CtiIe Cytopenia(s) U_ "as." =- "". more myeloid lineage -,,- -- ~aror """""" """... MPN _"" incleased;<2010 """" Usually oneormae ...... ...... Moy""Y ...... IariabIe. WBC ..-- Co<m>oo - rrft!lal cIyspIaSIa """" ....... ......, ........ ..-...... WllC_ -...... _>2ll%. "",", May Of may JIOl be """- """"""" ......... eQPl in some cases or e"ect1ve lIllh specific cybJeneIlc abnorrnaIilies or in -... dyspIaslailoneor some cases of erylhroIeukaemia Mf)N, myeloproliferative neoplasms: MDS, myelod)spla:slic syndromes; MDSlMf)N, myeIodysplasbcJmyeloprolifefalive neoplasms: AMl, ICIJIe myeloid leukaemia; ET, esseflIlaj Ihfombocylhaemia, JMML. ju¥&nile myelomonocytic leukaemia, wec. wniIe bloocI e&II$. 18 Introduction and overview of the c lassif ication of the mye loid neoplasms..
  • 18. ] alpha (PDG FflA) Of platelet de rived growth is based on cr iteria applied 10 initial spec- factor recep tor beta (PDGFRB) genes imen s obtained prior to any definitive ther- -a subgroup defined larg er9 by genetic apy, includ ing growth lactor therapy, for the events that lead to consti tutive act ivat ion myeloid neoplasm. The blast percentage in of the receptor tyrosine kinase, PDGFA, the per ip her al b lood , bone ma rrow an d and that respond to PTKI therapy {13 1, other involved tissues remains of p ractica l 466. 8121 . Similar examples are found impo rtance to categorize myeloid neo- througho ut the classification in each plas ms and to judge their progression . 11111111 111I 1111 1111 111111 major subgroup, and inclu de not only Cytogenetic and molecular genetic stud- neoplasms assoc iated with rmcroscopr- ies are requ ired at the time of d iag nosis 456 cally rec og niza ble chromosomal abnor- not only for recoq r n ton 01 specific genet- FS!. 1.01 Bone marrow tIeI:Me biopsy, Bone marfOW malities but also with gene mutations ically d efined entities, but for establiShing bephinebiopsies should be alleast 1. em in length and 5 without a cytogenetic correlate as weu. a baseline against which futu re studies ollt<w1ed at right angles10 the cortical bone. On the other hand . the importance 01 can be judged to assess disease pro- careful clinical, morphological and im- gression. Beca use of the multidisciplinary munophenotypic characterization of each approach req uired to diagnose and clas- cells to categorize some eoutes. it is rec- myeloid neoplasm and coeretanoo with sify myeloid neoplasms it is recomnended ommended that 500 nucleated BM cells the genetic findings cannot be over- thaI the various diagnostic studies be be counted on cellular aspirate smears in emphasized. The discovery of activating correlated with the clinical findings and an area as close to the particle and as JAK2 mutations has revolutionized the reported in a single, integ rated report. If undiluted with blood as possible. Countll"lQ approach to the diagnosis of the myelo- a definitive classification cannot be from multiple smears may reduce sam- proliferative neoplasms (MPN) 1163, 1044 , reached the report should indicate the pling error due to irregular distribution of 1186,12681. Yet JAK2mutatiQns are not reasons why and provide guidelines for cells. The cells to be counted include specific for any single clinical or morpho- additional studies that may clarify the blasts and promonocytes (see definition logic MPN phenotype, and are also diagnosis. below) . pronveocvtes. myelocytes, meta- reported in some cases 01 myelodysplas- To obtain consistency, the following myelocytes, band neutrophils, segmented tic syndromes (MDS), myeiooysplasnc/ guidelines are recommended for the eval- neutrophils, eosiropnns. basophils, fTlQIlO- myeloproliferative neoplasms (MDSlMPN) uation of specimens when a myeloid neo- cytes , lymphocytes. plasma cells , erythrOid and ac ute mye loid leu kaemia (AMl). plasm is suspected to be present. It is precursors and mas t cells. Megakaryo- Thus, an integ rate d, multidisciplinary assu me d tha t this evalua tion will be pe r- cvtes. including dysplastic forms. are not approach is necessary for the classification formed with full knowled ge of the clinical inc lude d. If a concomitant non-mye loid of myeloid neoplasms. history and pertinent laboratory data. neoplasm is present, such as p lasma ceu With so muc h yet 10 learn, there may be myeloma, it is reasonable to exclude some missteps" as trad itional approaches Morphology tho se neo plastic cells from the coun t to categorization are fused with more Periphera l blood: A perip heral b lood (PB) used to evaluate the myeloid neop lasm. If rrcecuarfy-orentec clessifcaton schemes , smea r sho uld be exa mined and co rre- an aspirate ca nnot be obta ined du e to Nevertheless, thi s revi sion of th e WHO late d with result s of a co mple te b loo d fibrosis Of ce llular packing, touch prepa- classification is an attempt by the authors, c ount. Freshly mad e smea rs shou ld be ratio ns of the b iop sy may yield valuable editors and the c linic ians who served as sta ined with May-Gnmwald -Giernsa or c yto log ic informa tion, but d ifferential members of the Clinica l Advisory Com- Wright-G iemsa and examined for wh ite co unts from touc h preparations may not mittee (CAC ) to p rovide an "evidence- bloo d ce ll (WBC) , red b lood ce ll (AB C) be repr esentative . The d ifferential co unts based" c lass ifica tion that ca n be used in and plate let abnormal ities It is impo rtant obta ined from marrow aspi rate s should daily p ractic e for therap euti c deci sions to ascerta in that the smears are we ll- be compared to an estimate of the p ro- and yet pr ovide a flexib le framework for stained, Evaluation of neutrophil g ranularity po rtions of cells o bserved in avai lab le integration of new data , is imp ortant when a myelo id d isor der is biop sy sections, suspected; de signat ion of neut rophils as Bone marrow trephine biopsy: The contri- abnormal b ased o n hypog ranular cyto- but ion of adequate 8M bio psy sections in Prerequisites for classification plasm alo ne shoul d not be conside red the diagnosis of myeloi d neoplasms can- unless the stain is well-controlled . Manual not be overstated. The tre phine biopsy ofmyeloid neoplasms by 2OO-cell leukocyte di fferentials of PB provides information rega rdin g overall WHO criteria smea rs are recommended in patients with cellularity and the to pog raphy, propo rtion a myeloid neoplasm when the WBC count and maturation of baematopolenc cells , The WHO c lassification of myeloid neo- permits. and allows evalu ation of 8M stroma. The plasms relies on the morphologic, cyto- Bone manowaspirate: Bone marrow (BM) biopsy also provid es material for immuno- chemical and immunophenotypic features as pi rate smears should also be stained histochemical studies th at may have of the neop lastic cells to esta bl ish thei r with May-G rQnwald-G iemsa or Wright- diagnostic and prognostic importance. A lineage and deg ree 01 ma turation and to Gie msa for optimal visua lization of cyto- biopsy is essential whenever there is decide whether cellular p rolife ration is plas mic g ranules and nuclear chromatin. myelofibrosis, and the classification of sore q101ogica lly normal or dysplastic or Because the WHO Classification relies on entities , partiCularly MPN, relies heavily on esecuve or ineffec tive . The classification percentages of blasts and other specific trephine sections, The specimen must be Introduction and overview of the ctassncauoo at the myeloid neoplasms 19
  • 19. adeq uate, Iake n at rig ht angle from thecortica l bone and at least 1.5 cm in lengthto enable the evaluation of at least 10 par-tially preserved inter-trabecular areas. Itshould be well-fixed, thinly sectioned at3-4 micra, and stained with haematoxylinand eosin and/o r a stain such as Giemsathat allows lor detailed morphologic eval-uation . A silver impreg nation method forreticulin fibres is recommended andmarrow fibrosis graded according to theEuropean consensus scoring system122141, A periodic acid-Schitt (PAS) stainmay aid in detection 01 megakaryocytes.Immunohistoc hemical (IHe) study of thebiopsy is often indispensable in the eva l-uation of myeloid neoplasms and is dis-cussed belOw,Blas ts: The percentage of myeloid blastsis important for dl8gnosis and ctasstcatonof myeloid neoplasms , In the PB the blastpercentage should be derived from a200-cell leukocyte differential and in the8M from a 500-cell count of cellular 8 Maspirate smears as described above . The biopsy. not all blasts express CD34 . They are usually strongly positive for n0n-blast percentage derived rom the 8 M Myeloblas ts. monoblasts and megakary<> specific esterase(NSE) but have no or onlyaspirate should correlate With an estimate blasts are included in the blast count. weak myeloperoxidase (MPO) activity,of the blast percentage in the trephine Myeloblasts vary from slightly larger than Promonocytes are considered as rrooo-biop sy. although large foca l clusters or mature lymphocytes to the size of mono- blast equivalents " when the requisite per-sheets 01 blasts in the biopsy should be cvtes or larger. with moderate to abun- centage 01 blasts is tallied for theregarded as possible disease progression. dant dark blue to blue-grey cytoplasm. diagnosis of acute monoblastic . acuteImmunohistochemical staining of the BM The nuclei are round to oval with finely monoc ytic and acute myerorronocyncbiopsy for CD34+ blasts often aids in the granul ar chromatin and usually several leukaemia. Promonoc vtes have a deli-correlation of aspirate and trephine biopsy nucleoli. but in some nuclear irregularities cately convoluted. folded or groovedfindings, although in some myeloid neo- may be prominent. The cytoplasm may nucleus with finely dispersed chromatin,plasms the blasts do not express CD34 , contain a few azurophil granules (Fig 1,03), a small , indistinct or absent nucleolus,Flow cyto metry determination of blast Monob lasts are large cells with abundant and finely granulated cytoplasm (Fig 1.04percentage should not be used as a sub- c ytoplasm that can be light grey to deeply C, 0), Most promonocytes express NSEstitute for visual inspection. The spec imen blue and may show pseudopod formation and are likely to have MPO activ ity. Thefor flow c ytometry is otten haemoouute. (Fig 1.04 A. S). Their nuc lei are usually distinct ion between mono brasts andand may be affected by a number of pre- round with deli cate , lacy chromatin and prornonocvte s is often difficu lt. butanalytic variabl es. and as noted for the one or more large prominent nucleoli. because the two cell types are summated ... ., •20 Introduction and overview of the classification of the myeloid neoplasms
  • 20. as rr onootasf s in making the diagnosis ofAML, the distinction between a monoblastand promonocyte is not aly,.ogys critical.On the other hand , distinguishin g pro-monocvtes from mo re matu re b ut ab-normal leukaemic monocytes can also bedilficult, but is critical, because the des-ignation 01 a case as acu te monocytic oracute myelomonocytic leukaemia versuschronic myelomonocytic leukaemia oltenhinges on this distinclion . Abnormal A Brrooocv tes have more clumped chromatinthan a p romonocyte, variably indented.folded nucl ei and grey cytoplasm with ,rrore abundant lilac -colored granules . Nu-cleoli are usually absent or indi stinct (Ftg 1.04 E.F). Abnormal monocytes are rotconsider ed as monoblast eouvaeots.Megakaryoblasts are usually 01rreoen tolarge size with a round , indented or ~~ - .irregular nucleu s with finefy reticularchromatin and one to three nucleoli. ThecytOplasm is basophiliC, usually agranular,and may show cytoplasmic blebs (See • •Chapter 6 on acute myeloid leukaemia,NOS). Small dysplastic megakaryocytes c oand micrornegal<.aryocyt es are not blasts.Inacute promyelocytic leukaemia, the blastequivalent is the abnormal promyelocyte .Erythroid precursors (erythroblasts) arerot included in the blast count except inthe rare instance of "pure" acute erythroidleukaemia, in which case they are cons id-ered as blast equiva lents (See Chap ter 6on acute myeloi d leukaemia, NOS).Cytochemistry and other special steins:Cytochemical stud ies are used to deter-mine the lineage 01 blasts, althou gh insome laboratories they have bee n sup- E Fplanted by immun ologi c studies usin gflow cytometry an d/or immunohistochem - Fig. 1.04 Monoblasts, promonocytes and abnormal mcnccytea from a case of acute monocytic laukaemia.istry. They are usu ally perform ed on PB A, B Monoblas tsarelarge with abundant cylOlJlasm that ma y contain a few vacuoles Of fine granules and have roullCland 8M aspirate smears but some can be nuclei withlacy chroma~n and one Of more variably prominent nucleoli. C, D Prornor.ocytes have more irregular anclperformed on sections 01 treph ine b iop - delicately folded n~ withfine chroma~n, small indistinct nucleoli and finely granulated cytoplasm. E, F Abnormalsies or other tissues . Detec tion 01 MPO monocytes appear immature, yet have mo condensed nuclear chroma tin, conoQ/uled Of fdded nuclai, and more re cylopIasmiC granulaboo (Courtesy of Or. J. Goasguen).indicates myeloid d ifferentia tion b ut itsabsence does not exclude a myeloid lin-eage because early myelobl asts as well case light grey granules are seen rather inhibi ted by NaF, The combination of NSEasmonoblasts may lack MPO. The MPO than the deeply black granules that char- and the specific esterase , naph thol-ASD-activity in rrweiobtasrs is usually granular acterize mverobrasts. The non-specific chloroaceta te esterase (CAE), which stainsand etten concentrated in the Golgi region este rases . u nap hthyl butyrate (ANB) and primarily cells 01 the neutroph il lineagewhereas monobtasts. although usually (,( naphthyl acetate (ANA). show diffuse and mast cells, permits ident ification ofnegative,may show line, scattered MPO+ cytoplasmic activity in monoblasts and monccvtes and immature and maturegranules, a pattern tha t becomes mo re monocytes. Lymphoblasts may have foca l neutroph ils simultaneously. Some cells ,pronounced in prcmonocvtes . Erythroid punctate activity with NSE but neutrophils particularty in myeIornonocytic leukaemias,blasts, megakaryoblasts and Iymphoblasts are usually negative. Megakaryoblasts may exhib it NSE and CAE simultaneously.are MPO negat ive . Sudan Black B (SSBl and erythroid b lasts may have some mul- While norma l eosinoph ils lack CAE, it maystaining parallels M PO but is less spe- titocal. punctate ANA positivity, b ut it is be expressed by neop lastic eosooohne.etc. Occ asional cases of lymphoblastic partia lly resistant to natrium ffuorid e (NaF) CAE can be performed on tissue sections leult.aemia exhibit SSB POSitiVIty in which , inhibition whereas monocyte NSE is totally as well as PB ()( marrow asp irate smears. Introduction and overview 01 the ctass.tcanoo 01 the myeloid neoplasms 21
  • 21. In acute erythroid leukaemia. a PAS stain an essential tool in the cha racterization of immunophenotyping in myeloid neoplasmsmay be helpful in that the cytoplasm of myeloid neoplasms. Differootiation antigens is most com monly required in AML and inthe leukaemic oroervmrobreate may show that appear at various stages of haemato- determining the phe notype of blasts atlarge globules of PAS positivity. Well- ooeuc develo pment and in correspon- the lime of transfo rmation of MOS.controlled iron stains should always be ding myeloid neoplasms are illustrated in MOS!MPN and MPN,per formed on the 8M aspirate to detect Fig . 1.05. and a thorough descriplion of Mulliparameter flow cytometry is theiroo stores. normal side roblasts and ring lineage assignment criteria is provided in prefer red method of immuno phenotypicside robrasts. the latter of which are de- the chapters on mixed phenotype acute analysis in AML due to the ability to ana-fined as erythroid precursors with 5 or leukaemia, The techn iques employed and lyze high numbers of cells in a relativelymore granules of iron encircling one-third the antigens anafyzed may vary accord- short period of time with simultaneousor more of the nuc leus. ing to the myeloid neoplasm suspected recording of information about severer and the information required 10 best char- antigens for each individual cell. Usually.Immunop henotype acterize it as well as by the tissue avail- rather extensive panels of monoclonal an-Immunophenotypic analysis using either able. Although often important in the tibodies directed against leukocyte differ-multiparameter flow cytometry or IHe is diagnosis ol any haematoiogicaJ neoplasm. entiation antigens are applied because <-U II 7+ - C U 1I7+ c m l 7- lib- llb-I+ C U,J. - C O lJ5.- C D.l6- CDIJ ~- fh+ C DJ6 - Cll1J~.- "" CD l 6 - C D235. - prvQ)"lbn>bla. 1 b ....p bllk: pc.ol ycbrvm.lk tory l b rub l.,. toryl h ruh l• • 1 C U lM- + C I)l63+ C IUJ+ C IU+ C O}4... C O IS+ C OU + C IU + C IU J + C O l5-+- C D36-+ COll ++ C D U" C I)6" + C DJ .... IIr"",,::7:-:-~01 liLA-DR" C IU 3" HL- -DR + C OM+ C U34_ C O ll b+ IH...A-O R + liLA -DR t-tl L -"-LO"--l,. C D I 4+ C O l lb++ C U.H++ • • C O l -t-t mon.. hl . ~1 p rumo"ucy m nmx: yl f ,-------, r----, em s- C O Il 7 +1- C IH J d lm C lU J " C ll1 J+ C IU J + MO+ C D 33 + MPO+ C D6 5+ MPO+ C ))65+ C U15+ C:0 6 5+ C D I5 + C D I I II+ C D I5+/· C U ll b+_ C1U 5tlim C D 3.. +-+ e m s- 1I1.A.-UR C D .N+-+ Un _ C D J ..... C IH M+ C D U J- C1U5R A+ _n_ C UJ4+I. C DJ4· C U.14- C D3.. + C DJ M., _ C DJ8+ ClHM _ C O. II++ C D61+ C 06 1+ C I)6 I++ C D IlJ-. C I).&I+ C 04I + C I).& 1-+-+ C1 U 5 HA - ce-e- C04 l +I· C U" l+ TIO -R+22 mtrocucuco and overview of lhe classification of the myeloid neoplasms
  • 22. J the utility o f in,s:livid ual markers in identify- in the id entification of abnormal mega- Revised WHO classification of ing commitme nt of leukaemic c ells into ka rvoc ytes. myeloid neoplasms the different haemat op oieti c tlneages is limited Evaluation of exp ress ion patterns Genetic studi es of several antige ns, bo th membrane and The WHO classi fication includes a num- Table 1,0 1 lists the major subgroup s of cytoplasmic, is necessary for lineage be r of entities defined in part by scecmc myelold neop lasms and their characteristic assignment. to d etect mixed phenotype genetic abnormalities. including gene features at diagnosis. The nomenclature acute leu kaemia, and 10 detect aberran t rearrangemen ts due 10 chromosomal for the myeloprolife rative entities has been phenotypes allowing lor follow-up of nansrccarrons and to specific gene muta- c hanged from "c hronic mye lopro liferat ive minimal re sidua l d ise ase . tions. so de term ination of genet ic features diseases" to ·myeIoproIiferative neoplasms" Irrmunopheootypic analysis has a ce ntral of the neoplastic cells must be performed and the subgroup formerly designated as role in disting uishing be tween minimally if possible. A complete cytogenetic ana ly- "myelod ys pl as ticfm y e lo p ro li fe rati v e dllferentiated acut e myeloid leu kaemia sis of 8M shou ld be perlormed at the time dis eases" has been ch ang ed to and acute lymphoblastic leukaemia, and of init ial eva luat ion to establish the cyto- "myelod ysplasticJmyelo proliferative ne0- in CML between myeloid blast pha se genetic profile, and at regu lar intervals prasms" to und erscore the ir neoplast ic and lymphoid blas t phase. Among AM L thereafter to detect evidence of genetic nature . Beside s the addition of the new WIth recurrent genetic abnormalities , sev - evolution . Additional d iag nosti c genetic subgroup. "Myeloi d and lymp hoid ne0- eral have characteristic phenotypes. These studies should be guided by the diagnosis plasms with eosinophil ia and abnormalities patterns. described in the respective suspected on clinica l, morpholog ic a nd of PDGFRA, PDGFR8 and FGFRt ,· new sections, can help to plan molecular cvto- imTulophenotypi studies. In some cases, entities have been added and/or diag- genetIC {lluorescence in situ hybrid ization reverse transc rip tase-pol ymerase c hain nost ic criteria updated with in each sub- (FISHlI and molecular inv estigation s in reaction (AT-PCR) and/or FISH may de- group. individual patie nts, lm munophe notyp ic tect gene rearrangements thai are pres- features or the other AMl categor ies are ent in low frequency and not observed in Myeloproliferative neoplasms (MPN) extremely heterog eneo us. probably due the initial chromosomal ana lysis, in c ases The MPN (Table 1.02) are c lonal haeretc- to high genetic d iver sity. Although it has with var iants of typical cytogenetic porenc stem cell d isorders Characterized been sugges ted that express ion of c er- abnormalities, and in cases in which the by pr oliferation of one or more of the tam antiqens, such as CD?, COO, C Ol lb, abnormality is cryptic , such as the myel oid lineages (l.e. granulocytic , ery - C014. CD56 and CD34 cou ld be associ- PDGFRA-FIP1L 1 fusion in myeloid neo- thro id . megakaryocytic and mast cell). ated with an adver se prognosis in AMl, plasms associated with eos inophilia, De- They are primarily neoplasms of ad ults their independe nt prognostic value is still pending on the abnormality, qu ant itative that peak in frequency in the 5th to 7th controversial. Aberrant or unusual omoro- PCR performe d at the time of diagnosis decade, but some subtypes. parti cu larly phenotypes have been found in at may also p rovide a baseline against CM l and essential thrombocythaemia least 75% of ca ses of AMl. These c an be whic h the response to therapy c an be (ET), are reported in children as well. The described as c ross-lineage antigen ex- monitored . A num ber of gene mutations inc id enc e of all sub types combined is pression, matura tional as ync hronous d etect ed by gene sequencing, allele- 6-10/ 100,000 population annually {1053, expression of antigens , antigen overex- spe cific Pe A and othe r techniq ues have 1059. 1060 f, pression, and the red uction or abse nce of em erge d as importa nt diagnostic and Initially. MPN is cha racterized by hyper- antigen expressio n, Sim ilar aberra ncies prognostic ma rkers in all ca tegories of cellularity of the BM with effective have also been reported in MDS as well. mye loid neoplasm s, Mutat ion s of JAK2, naematoporetc maturation and increased and their presence ca n be used to sup port MPL , NRAS, NFl , PTPN 11, and KI T in numbers of gra nulocytes, red blood ce lls the diagnosis in ear ly o r morpholog ica lly MPN and MDS/MPN, and NPM1, CEBPA, and/o r plate lets in the PB. Splenomegaly ambiguous cases of MDS (See Chapter 5). FLT3, RUNX1 and KIT, among others. in and hep atomeg aly a re co mmon and lm11unophenotyping by IHC on 8 M b iopsy AMl are impo rta nt for d iagnosis and caused by sequestration of excess b lood sections can be applied if ma rrow cell p rognosis. and some. particularly JAK2, cells or proliferation of abnormal raemato- suspensions are nol available for flow cy- FLT3, NPM 1 an d CE8PA figure impor- poietic cells, Despite an insidious onset tcmetry analysis. Antibodies reactive with tantly in this revised classification . Fur- each MPN has the potential to undergo a paraffin-embedded BM biopsy tissue are thermore , the role of gene over- and available for many lineage-associated unde r-expression as well as loss of het- Table 1.02 ~live neoplasms (MPN) . markers (e,g. MPO.lysozyme, CD3, PAX:s, e rozygosity and copy number variants C033, etc.). As noted previously, CD34 detected by array-based approaches are ChrtncITl)9logenous 1Bukaenia, BCR-ABI. posibYe (CMl) staining of the biop sy can fac ilitate the on ly now being recognized as impo rtant detection of blasts and their distribution , abnormalities that may well influence Clwtlnic. neutrophilic leubeml8 (CNL) provided the blasts expres s CD341 1650/. d iagnostic and prognostic models in the ~oefil (PV} For cases rich in megalob lastoid erythro- near future 11531AI . Nevertheless, """" _ _ (PM~ blasts. immunohistolog y for glycophorin m icroarray prof iling studies. alt hough ESSoElIIUl ~ (ET) "- or haemoglobin may be helpful in dist in- import ant in the research setting , have not Oworic eosnophic Ieukaerru. NOS lea NOS) guishing those cells from myeicotasts yet been tested in cl inic al practice . (eg. in cases of RAEB or acute erythro- MyelqiltMaabYeneoplasm,loIldasslJable (UPN,U) 1eI.Memia), and COOl or CD42 oflen aid introouctco and overview of the ctassrncanon of the myek>id neoplasms 23
  • 23. CML ABU Myeloid neoplasms PDGFRA,PDGFRB,FGFR1 with eosinoph ilia PV JAK2 V617F, JAK exon 12 PMF JAK2V617F, MPL W15 1UK ET JAK2V617F, MPL W151 UK Mastocytosis KITD816V Fig. .06 Myeloprololerative neoplasms (t.4PN)and oIhet myeloid neoplasms associated W11t1 mutaliOnlrearrangement of tyrosine kinase genes. stepwise pr ogr ession that term inate s in subtypes of MPN from each other but these genetic abnormalities. such as the marrow failur e d ue to myelofib rosis , inef- from reacti ve granulocyt ic . erythroid andl BCR-ABL1 fusion gene in CMl . are esso- fective haemat opoi esis or Iransformalion or megakaryocyt ic hyperplasia . cia ted with consistent clinical, laboratcry 1 an acu te blast phase. Evid ence of ge - 0 Revisions in the criteria for cla ssification and morp hologic find ing s that allow them netic evo lution usually heralds disease of MPN in the cu rrent scheme have been to be utilized as major criteria for classfi- progression as may increasing organa- influen ced by two fac tors - the recen t cation, whereas others provide proof that megaly, increasing or decreasing blood discovery of gen etic abnorm alities in- the myeloid prolifera tion is neoplastic counts , myelofi brosis and onset 01myelo- volved in the pathogenesis of BCR-ABL 1 rather than reactive. dysplasia. The finding of 10-19% b lasts negative MPN and the wide r appreciation Ac quired somat ic mutations of JAK2. at in the P8 Of 8M generally signi fies accel- that histologic features (megakaryocytic chromosome 9p24. have been shown);) erated disease and 20% or more is morp hology and topograph y, marrow playa p ivotal role in the pathogenesis d suHicient for a di ag nosis 01bla st pha se . stromal changes, id entific ation 01specific many cases of BCR-ABL 1 negative MPH cell lineages involved in the proliferation) 11 04 4, 1163, 1186, 1287A , 12881 The . Rationale for tho diagnosis and cor relate with clin ical features and c an be most comm on mutation , JAK2 V6 17F, re- classification of MPN used as criteria to identi fy MPN subtypes sults in a constitutively active cytoplasmic In previous cl assification schemes the {2 177. 22 16, 22221. JAK2 that activates signal transducer and detect ion of the Philadel phi a chromo- Mo st if not all MPN are assoc iated with ac tivator of transcription (STAT), mitogen some and/or BCR-ABL 1 fusion g ene was clona l abnormalities involving g enes that activated p rotein kinase (MAPK) and[ used to coolirm the diagnosis of C Ml wher eas the remaining MPN sub types encode c ytoplasmic or receptor PTKs. The abnormalities described to da te phospholidyllnositol a-kmase (P13K) sigo naling pathways to prorote transforma1Ol were diagnosed by their cli nical and include transicc anons Of point mutations and proliferation of baemaroooenc pro.j labo ratory features with relatively minor contributions to the diagnosis from mor- of genes that result in abnormal, co nstitu- tively abnormal PTKs that activate signal g enitors (Fig. 1.07). The JAK2V617Fmu- tation is found In almost all patients wit~ ph ologi c findings. A number of criteria transdu cti on pathw ays leading to the polycythaemia vera (PV) and in n ear~ were required not only to distinguish abnormal proliferation . In some c ases, one-half of those with primary myelofil:Jrosis 24 Introdu::tion and overview of the classi fication of the myeloid neoplasms
  • 24. (PfvlF) and wit~ esseotelmoroocvmaera a and ab normalities 01 PDGFRA. PDGFRB or their relevan ce are in progress and revi-(ET), In the few PV patients wno lack the FGFR1 , If none of the se rearrangements sions may be necessary.JAK2 V6 17F, an acti vat ing JAK2exon 12 are d etec ted, and there is no BCR-ABL 7mutation may be fou nd , and in a small fusio n gene , they should be ca tego rized Myeloid and lymphoid neoplasms withproportion of cas es of PMF and ET, an ac- as GEL, not otherwise specified eosinophilia and abnormalitie s oftivating mutation 0 1 MPL W5 15l or W5 15K 4. The d iagnostic al go rithms for PV, ET PDGFRA, PDGFRB or FGFR1is seen. It is important 10 no te that JAK2 and PMF ha ve been substantially De termi ning the ca use of marked , per-V617F is not specific for any MPN nor c hanged to incl ude infor mation rega rd ing sistent eosinophilia (~ 1 .5x1()9/l) in thedoes its absence exd ude MPN . Further- JAK2 and similar ac tivat ing mutations as blood can be challengi ng and is some-more, it has been reported in some cases well as pertinent histolog ic featu res 01 the times cli nically urg ent beca use 01 theof MDS/MPN, in rare cases of AMl, and 8M biopsy as d iag nostic Criteri a. potential damage to the heart, lungs , cen-incombination w ith other well-defined ge- 5. The threshold of the p latelet count for tral nervous and other organ systemsnetic abnormalities such as the BCR-A8L 7 the di ag nos is of ET has been lowered to caused by the eosinophilic infiltration and1 10641. Thus, diagnostic algorittvns for PIl, ~4 5Ox 1 Q91l. release of cvtocnes. enzymes and other ET and PMF have been altered to take the 6. Crit er ia for CMl in accelerated phase proteins. The eoeoooous may be derivedmutationalstatus of JAK2 into account as have been suggested w ith the caveat that from the neoplastic clone of a myeloid weN as 10outline the additional laboratory they have not been fully evaluated in the neoplasm, such as GEL, GMl or AMl, or and histo6ogic "ndi~JS required to reach era of PTKI therapy: studies 10 determine lhey may be reactive due to abnormal an accurate classification 01 c ases, re- gardless 01 whe ther the mu tation is or is not present. In addition to the changes in the cr iteria B lor N , ET and PMF, information reg ardi ng A abnormal PTK toncnon due to rearrange- mentsof the POGFRA, PDGFRBor FGFR1 genes in patients with myeloid neoplasms associated with eosinop hilia led to reap- praisaland new diag 1ostiC algorithms for those syndromes as well (see below). The appreciation 01 the role altered PTKs pla y in the pathogenesis of C Ml, PV, ET and PMF also argues lor the inclusion of simi- lar chronic myelo id pronteranons related ~ I 10 PTK abnormalities under the MPN um- I brella. Thus, systemic ma stocytosis, wh ich Akt (0 has many features in common with other I MPN entities and is alm ost always asso- ciated with D816V mutation in the KIT ¥ TO "FoxO " -., E0 geneencoding the recep tor PTK, KIT, has I been added to this categ ory 121761 St ill, tI"1e molecular pathogenesis of nearly half of all cases of ET and PMF, of all cases of I X ~0 @jJ I chronic neutrophilic leukaemia and a m ber of myeloid neo plasms ass oc iated m with eosinophilia remai n unkn ow n . For these reliance on cli nical, laboratory and -- ----- -- Activation of gene!o Important in proliferation and survival morphologic features is essenti al for diagnosis and classification, Stmnary 01major c hanges in the classilication of MPN or Fig. 1.07 MecRanism activatiOn aI JA1<2 kinase actMty by rn.rtaIiOns in the JAK2 Signalirg pathway It. Cytokile . I . The nomenclature , mveiopronte ranve ligallds normaHy bind cytokine recepIors, .tlich results in JaIllS kiase 2 (JAK2) pIlosphoryIatio, recruilmenI aIsq.at disease" has bee n changed to "myelo- rcInsduc:er and actrvator allJansaipbon (Stal) signaling protelns and pIlospholyIation alld activatiOn of downstream proliferative neoplasm " SigRaIing pathways ind.I:lIng SIal ~ lactor&,lTIlogefIlIdMlled proIeIn U1ase(MAPK) sigMWlg proteins , arIl the phosphotidyinos 3-kinase (Pl3K)--Akt pathway B The JAK2 Vfi17F alld JAK2 ewn 121Tl11anl kilases bind 2, Mastocytosishas been includ ed in the cytokine recepIors, are phosphorylated il the absence alligand and lead to ~ activation aI 0JwIn. MPN category streamsignaing palhways. C Bycontrast, MPl. W515lA( rrUallllhiOi~ recepb$ are able 10 phospI1Oiyale 3 Some cases previously meeting th e ri1-Iype JAK2lithe absence 01 hanbopoleIi., and red II tle aetwabon of signaling paltrways <townstream 01 IN<2. Cfllena for chronic eosinophilic leuka emia Negative regulation 01 JAX2 sigNIng is nonnaIy medIaIed by suwessor of cytome s9laIilg (Socs) proWls, most (CEll may now be categorized as myeloid notably SOCSl alld SOCS3; recent dala ildic3Ie Ihalthe JAK2 V617F aIeIe night escape negatiYe IeectIacll by (J ~ d neop lasms with eosinophilia SOCS3. Repro:U;:ed from {1287AI Introduction and overview of the classification 01 the myeloid neoplasms 25
  • 25. cytoki ne relea se from reactive or neo- Although it might seem most efficient to TableU4 ~neopIasms (MDSlMPN).plastic r -ceus. In a numbe r of ca ses. no categorize these cases as CEl withinunderlying cause can be fOund and the MPN, this would ignOfe cases WIth cmnc myelomonocyllc leukaenU (CMMl)clonahty of the eos inophils ca nnot be PDGFRB abnormalities that present as Atypocal chrooiC myeloid leukae~ ,proven: these cases are app ropriately CMML as well as cases of FGFR1 and BCR -ABLI negative (aCMl)termed "idiopathic hypereosinophilic ssn- PDGFRA rearrange ments that may even JIMIrIiIe myelomooocytic leukaemia ("" Ml)drome" (See Chapters 2 and 3). have a lymphoid conoooenr. To accom- MyekldysplastcIMyeloproliferative neoplasm, mod ate Ihese transiccatons. a new sub- undassdiable (MDSlMPN ,U)Rationale for diagnosis and classification group defined largely by the genetic Provisional entity: Refractory anaemia wittl Mrlgof myeloid and lymphoid disorders with abno rma lities of PDGFRA, PDGFRB or sideroblasts and ltJramt>ocytasis (RARS-neosinophilia and abnormalities of PDGFRA, FGFR1 has been added (Table 1.03).PDGFRB or FGFR, Detect ion of one of these abnormalitiesSince the last edition of the WHO c lassifi- places the case in this category, regard- should not be categorized as MDS/MPN.cation it has been recog nized that many less at the morpholog ic classification. and in contras t to the criteria used in thecases of eosinophilia, incl udin g a sub- Cases of myeloid neoplasms with 3rd edition of the WHO classification,stantial number conside red as "idiopathic" eosinophilia that lack all of these abnor- cases of CMML with PDGFRB rearrange-are clonal myeloid neoplasms caused by malities and that meet the criteria for ments are also excludedabnormalities in genes that encode the CEL. NOS, in the MPN catecov shouldalpha or beta chains 01 the receptor PTKs, be placed in that group. Rationale for diagnosis and classificationplatelet derived growth factor receptor of MDSlMPN(PDGFR) or fibrobl ast gro wth fac tor reo Myelodysplastic/myeloproliferative This diagnostic ca tegory was introducedce ptor 1 (FGFR1), Rearrangements 01 neoplasms (MDSlMPN) in the 3rd edition amidst controversy as toPDGFRB at chromo some band 5q33 that The MDS/M PN (Table 1.04) include clonal wl1ether some entities, particularly CMML,lead to constitutive activation of the beta myeloid neop lasms that at the time of ini- would be better categorized as eithermoiety of PDGFA were first recogni zed in tial presentation have some clinical, labo- MDS or MPN depend ing on the extent ofcases variably reported as CEL or chronic rato ry or morphologic findi ng s that mye loprol iferation as evidenced by themyelomonocy tic leukaemia (CMML) with support a diagnosis of MDS, and other WBC cou nt. Some cases of CMML haveeosinophilia 11 31 , 8 12. 20851. More re- findings more consistent with MPN They low neutroph il co unts and only modestlycen tly the gen e that encodes the alpha are usually cha racterized by bvpercenu- elevated monocyte co unts and resemblemoiety of the PDGFR, PDG FRA, at chro- larity of the BM due to proliferation in one MDS clinically and morphologicallymosome band 4q12. was found to be or more of the myeloi d lineages . Fre- whereas others have markedly elevatedinvolved in cryptic translocat ions in CEl quently, the proliferation is effective in WBC counts and org anomegaly more inand in nearty one-half of cases reported some lineages with increased numbers of keep ing with MPN. yet criteria that clearlyas idiopathic hypereosinophilic syndrome circulating cells that may be morphologi- distinguish biologiCally relevant subtypes14661· In addition , rearrangements of the cally and/or func tionally dysp lastic . Si- of CMML remain to be defined .FGFR 1 tyrosine kinase gene have also multaneously, one or more 01 the other To date, a lew cases of CMML and atypi-bee n implic ated in myeio oronteratrons lineages may exhi bit ineffective prolifera- cal chronic myeloid leukaemia, BCR-ABL1with prom inent eosinophilia 13, 13541. tion so that cytopenlate) may be present neg ative (aCML) have been reported toHowever, the c linica l and morphologi c as well. The blast percentage in the BM demonstrate JAK2mutations that charac-presen tations associat ed with FGFR 1 and blood is always <20%, Although terize BCR-ABL 1 negative MPN, but therearrangement are variable, and include hepatosplenom egaly is common, the clin- prol iferative aspec ts of most cases ofnot only presentation as a myeloprolifera- ical and labo ratory find ings vary and lie MPD/MPN are related to aberrancies intive neop lasm with eosinophilia, bul also along a continuum between those usually the AAS/MAPK signaling p athways. In ju-as AML and they may even present as, or associ ated with MDS or those usually venile myelQmonocytic leukaemia (JMML)evolve to. precursor T or B lymphoblastic associated with MPN Patients with a well- nearly 80% of patients demonstrateleukaemia/lymphoma with prominent eo- defined MPN who develop dysplasia and mutually exclusive mutations 01 PTNPN1,sinophits Cases associated with PDGFRA ineffective haematopoiesis as part of the NRAS or KRAS, or NFl 11329. 2096,rearrangements can likewise present as natu ral history of thei r disease or after 21621. all of wl1ich encode signaling pro-AMl or precursor t -een neoplasms 114691. chemotherapy should not be placed in teins in AAS dependent pathways, and this category. Rarely, some patients may approximately 30- 40% of cases of CMMLTlb.. 1.03 Myeloid and lymphoid neoplasms W11t1 present in a transformed stage of an MPN and aCML exhibit NRAS mutations {1686,eosmphi lia ard abnormal~m ol POOFRA, POOFRB, or entity in which the chronic phase was not 231 1, 24171. In view of the lack of anyFGFR1 . reco gnized, and may have findin gs that spec ific genetic abno rmality 1 suggest 0 Myeloid and lymphoid neoplasms with suggest that they belong to the MDS/MPN that these entities should be relocat ed 10 PDGFRA real1"angement gro up. In such cases, if c linical and labo- another myeloid subgroup, they remainin rato ry stud ies fail to reveal the nature of this "mixed" category which acknowledges Myeloid nooplasms with PDGFRB rearrangemeot the und erlying proce ss, the designation the overlap that may occ ur between MDS of MDS/MPN, unc lassifiable may be ap· and MPN. Casesof CMML with eosinophilia Myeloid aoo IylTVIOid neoplasms wiltl FGFRf abnormallbes orcorare. Paneots wro have the BCR·ABL 1 associated with PfX3FR rearrangements B fusion gene or rearrangements of PfX3FRA are excluded , but rare cases of CMML nurooocuoo and overview 01 the classification of the myeloid neoplasms
  • 26. with eosinophilia that do not ex hib it such by mixed MOS and MPN features associ- 50% of the BM ce lls are erythroid precut-rearrangements sho uld be cJassified in ated with pro minent pseuoo-Percer-Hoet sors. an d for which ac ute eryt hroidthis categOry anomaly of me neutroot urs. low 8M blast leukaemia is co nsidered a po ssible dia g-The most controverstat issue in the su b- count, and a rap id ly p rog ressive clinical nosis. In such cas es. if blasts acc ount forgroup at MDSIMPN is the provisional entity. course. Most c ases rep or ted have a fewer than 20% of WBC in the PB and 01refractory anaemia with ring siderob lasts prominent monoc ytic component and all nucleated 8 M cells, and for less thanand thrombocytosis (RAR5-T). The ma jor- meet the c riteria lor CMML, b ut in some, 20% of the non-erythroid c ells in the BMity (SO- 60%) 01 cases of RARS-T studied the PB monocyte coun t may not reach the (lym phocytes, plasma c ells, etc. are alsolor JAK2V6 17F carry this mut ation 1234. low er threshold fo r that dia gnosis 1708, excluded in this latter calculation), the354.762 , 1835. 1839. 1969,2081,2139. 14371· In cases that do not fu" ill the c riteria case is considered as MOS. In this sce-23581 This has prompted the notion that . lor CMML or another well de fined myeloid nario. there is lac k of consens us amongRARS-T should be moved to the MPN category. desig nation as MOSIMPN. un- mem ber s of the WHO committee as togroup of myeloid neoplasms. whereas classifiable. with isolated isochromosome whether the MOS should then be classi-othershave argued thaI RARS-T is not an 17q abnormality, is most ap propriate. fied according to !he b last perceotace ofentity at all but merely one of the better all nucleated 8 M cells or according 10therecogniZed MPN entities, such as PMF or $urTmary of major changes in MDSIMPN blast percentage of all non-erythroid BMET. il which genetic evolution has led to a 1. Some cases of CMML with eosinophilia cells. but the majority recommend s thatdysplastic teanse. ring sideroblasls 11966. are relocated to the category, "Myeloid the MOS be classified using the blast per-2139. 23581. In a few cases reported. neoplasms with PDGFRB rearrangement" centage of all marrow nucleated cells.hl:1Never. the cells of patients with RARS-T. 2 . The c ategory, "Atypical CML" has been Many cases of refractory anaemia withwhen studied by in vitro cul ture tech- renamed as •Atypical C ML . BCR-ABL 1 ring sioerobrests as well as refrac toryniques, have growth characteristic more negative" to emphasize this disease is not anaemia have marked eryth roid prolifera-in keeping with MOS than MPN 1234, merely a va riant of BCR-ABL 1 positive tion and using the b last percentage of the18351. An additional question is hOw to CM L. non-erythroid cells lo r classification ofclearly distinguish RAR5- T from RARS, in 3 . RAR$-T remains as a provisional enlity, such cases might c ause these to bewhich moderately elevated pla telet classified as MDS/MPN . uncrassiuabre . placed in an unnecessarily high-risk cat-counts are etten repo rted . This question until furthe r data clarifies its approp riate egory. On the other hand , if there isis morepressing in view of the revised c ri- designation. The crite ria for its recognition severe multiline age dysplasia, very bizarreteria for RARS-T that lowers the p latele t have been modified. The platelet thresh- erythroid morphology. and/o r minimal orthreshold from ~x lrJl/L to ~450x 1rPlL, old has been lowered to ~ 45Ox 1rPll, and no maturation to segmented neut roobus.in parallel with the revised threshold lor meg akaryoc yte s w ith morp hology simil ar and the btast percentage of total 8 M cellsEf It is important to note that the d iag- to those seen in ETor PMF must be present is not sufficienl to place the c ase into anostic criteria for RARS-T include not only hig h-g rade MOS c ategory, the casethe Iinding of an elevated platelet coun t in Myeladysplastic synd romes (MOS) shoul d be flag ged tor clin ical co rrelationconjunction with anaem ia and ring elder- These disorders , usually characterized by an d discussion, with ca refu l follow- upoblasts in the 8 M, but al so mo rp hologi- the simultaneous prolifer ation and apo p- (Tab le 1.06 ). More stud ies are neededcallyabnormal megakaryoc ytes similar to tests of baematopoienc cells that lead to a however to cla rify this controversial issue.those of ET or PMF. Only a few pat ient s normal or nvoerceuurar BM bi op sy andwith RARS and plate let counts in the PB c ytopenia(s), remain among the most Acute myeloid leukaemia (AML)450,500x W 9/L rang e have be en studi ed c halleng ing of the myeloid neop lasms for AML is a d isease resul ting from the c lonalfor JAK2 mutat ions and in mo st with p rope r d iagn osis and class ification , The expansion of my eloid blasts in the PB,platelet counts in the lower rang es no mu- general fea tures of MOS, as well as 8M , or othe r tissue, It is a heterogeneou stations have been found . Neverth ele ss, specific gu ide lines fo r diagnosis and di sease c linically, mo rphologicall y andmore stud ies are need ed , and we rec om- c lassific ation are outlined in Chapter 5. ge neti cally and may involve only one ormend to test for JAK2 mutation s in pa- An impo rtant add ition to the MOS ca te-tents who have RARS and pl atelet counts go ry (Table 1.05) is the provision al entity,above the normal range . The sum of cur- refractory c ytopenia of c hild hood (RCG), Tabl. 1.05 Myelodysplastcsyndromes,rent information reg arding RAR5-T argu es This categ ory is reserved for c hildre n with Reffacto!y ~nia wlltlll1 iWleage dysfllas48for its continued placemen t in the MOS who have <2% b lasts in their PB and (RCUD)MDS/MPN category. but in view of the <5% in their 8M and pe rsistent cvtope- Reffa<:byanaemia (RA)debate regar ding its precise definition nia(s) with d ysp lasia , In contrast to MDS Refracloty neutropenia (RN) Refradcry ltuQmbocytopenia (RT)and nature, it is best reg arded as a with ref rac tor y cvtc oentee in eo utts. the Re!fadclry allaemia with ri1gSiderObIasts (RARS)provisional entity" until more data are majority of cases of ACC have hypoc ellular Relractory cytlpenia with ITIJlblineage dysplasiaavailable, 8M bio psy specimens, and the d istinction (RCMD)lastly. classification of myeloid neoplasms from acqui red apl astic anaemia and Refractory all8e/lM8 wiII1 excess bIasls (ME B)that carry an isolated isochromosome t 7q inherited BM fai lure syn dromes is often MyelodyspIa$llc syncWmewilI1 iSOIatecI dfll(Sq)and that have less than 20% bl asts in the c hallengin g 117841, Myelodysplllsbc syndrcIme. undas.sJliable (J.I>S.U)P8 or BM may prove difficult. Some au- An issue appro priate 10 menton at this C*hood ~ syrw:lromethOrs suggesl this cytogenetic defect Pn:MsicnaI nty Refra:t:ry ~ ~ d*hlod point is the cntene used for ctassmcatco (ROC)defines a unique disorder characterized of myeloid neoplasms in which more lhan Introduction and overview of me classification 01 the myelOId neoplasms 27
  • 27. ... . - T 1.06 PMSib1e d~ when erythroid precursors ~5010 of bone marrow nucleatedcells. able pathways to promote proliferation/survival - - % Erythroid ~ Blocdhnarrow findirlgl. 0ltIer f1odlng& DIagnosis A similar multistep process is also evident in AMl that evolves from MDS or that has myelodyspl asia-related features, often ~ blasts in blood or Case meets alteria lor AML With fllyelodyspIaSia of all nucleatedmarrow AMLwith my8lOdysplasia· characterized by loss of genetic material related changes related changes and haploinsufliciency of gene s. Within _01 the last few years, genetic mutations have ~ -_.- inmatln IJyIIwid Few • lit{ myeIclt:Qsts Miwnall <Wly PIn 8I)tWIlid IeWemia also been identilied in cytog enetically """"" ..., """" """""" -,-- normal AML 115321. Sane of the rrutations, matlJflllJon such as those of CEBPA and perhaps >5011 blasts <m d II fIm.>MiKi1I ~celsll """"" ....... NPM1 invdve transcriplion faclors. whereas erne-e. including those of FlT.J and NRASIKRAS. affect signal transduction. 50 """""- """"" .." Not only have these mutations led to an ... """"" <20% blasts in blood, Blasts <20% 01 all MDS: classifyMDS unde rstand ing of leukaemoc enests in blasts <20% of all ~roid cells in acx:oroing 10 number of c ytogenetic ally normal AML, bul they """" """""- blasts in blood and blasts have proved to be powe rful prog nostic as pen:entIge d II factors 115321. In summary, genetic ab- • Erythroid precursors , lymphoid cells andplasmacens aresubtracledfrom a" nlJdeatedma the"noo-erythroid eels" in thebone marrow. """""" """""- rrowcells to calDJlate normalit ies in AML eluci date the patho- genesis of the neoplasm, provide the most reliable prognoslic information, and will likely lead 1 dev elopment of more 0 successful targeled therapy.all myeloid lineages. Worldw ide the inci- matur ation, the d iagnosis doe s not nec- One of the challenges in this revision hasdence is app roximately 2.5-3 cases per essar ily translate into a mandate to treat been how to incorporate important and/or 100,000 popu lation per year, and is the pa tient for AML; c linical factors. in- recently acquired genetic information intoreportedly highest in Australia. Western cluding the pace of prog ression of the a classific ation scheme of AMl and yelEurope and the United States. The me- dise ase, most atways be taken into con- adhere to tile WHO principle of definingdian age at diagnosis is 65 years, with a sloerenon when deciding therapy. horoogeneOuS, biologically relevant entitiesslight male predominance in most c oun- based not only on gene tic studies or theirtries. In Children less than 15 years of age, Rationa le for the WHO diagnosis and prognostic value, but also on clinic al,AML com prises 15- 20% of all c ases of classification of AML morpho logic and/or immu nophenotypicacute leukaemia, with a peak incidence in The 3rd edition 01 the WHO ctassrncatoo studies . This was particular ly prob lematicthe first 3-4 years of lite 1559A, 2463AI. ushered in the era of formal incorporati on for the most frequent and progn osticallyThe requisite blast perce ntage for a diag· of gene tic abnormalities in the diagnostic impo rtant mutat ions in c ytogeneticallyrosrs of AML is 20% or more mveiobtasts algor ithms for the diagnosis of AML. The normal AML, mut ated FLT3 , NPM 1 andand/or monoblastslpromonocytes and/or abnormalities included were mainly ch ro- CEBPA. They have few or variably con-meg akaryo blasts in the P8 or BM. The di - mosomal transiocenoee involVing tran- sistent mor phologic, irrwnunophenotypicagnosis of myeloid sarcoma is synony- scription fac tors and associated with and clinical features reported to dale , andmous with AML rega rdless of the numb er charac teristic cl inical , morpholog ic and the mutation s are not mutuall y exc lusive.of b lasts in the PB or BM, unless the immunophenotypic features Ihat formed For the most par t, the framework coo-patient has a prior history of MPN a ·clinico-pathologic-genelic· entity. As structec in the 3rd edition proved flexibleor MDS/MPN, in wh ich c ase myeloid know ledge regarding leukaemogenes is enough to incor porate the new entitiessarcoma is evidence of acute transforma- has increased, so has the acceptance propo sed by membe rs of the WHO c0m-tion . The d iagnosis of AML can also that the genetic abnormal ities leading to rmttee and the CAC (Table 107). The en-be mad e when the blast percentage in leukaemia are not only heterogeneous, tities initially described in the subgroupthe PB and/or BM is less than 20% if but complex, and multiple aber rations · AML with recurring genetic ab normal-there is an associated t(8;21XQ22;Q22), often coo perate in a multistep proce ss to nee remain with only minor mod ificationsinv(16)(p 13.1Q22), t(16:16XP13.1;Q22) or initiate the co mple te leukaemia pheno- (Table 1.07) and three more entities, char-t(15;17)(Q22:q 12) chromoso mal abnor- typ e. Expe rimental evide nce suggests acterized by chromosomal transtocatioosmality, and in some c ases of acute ery- mat in many ca ses, although rearrange- associated with fairly unilorm morpholog-throid IeuI<aemia when eryttvoid precursors ment of genes such as RUNX1, CBFB or ica l and cl inic al features have beenac count for more than SO% of the BM RARA that enc ode transcncuon factors added . Cases with muta ted NPMl andce lls and blasts account for more impair myeloid differentiation, a sec ond CEBPA are added to the same subg roupthan 20% of the non-erythroid marrow genetic abnormality is necessa ry to pro- as provisional entities ind icating thatce lls (See Chapter on acute myeloid mote proliferation or survival of the neo- more study is needed 10 lully characterizeleukaemia, NOS). plastic clone (Fig . 1.08) 11135A I. Often. and estab lish them as unique entitiesAlthough the diagnosis of AML using the the additional abnormalities are mutations Although mutated FLT3 is not includ ed asabove guidelines is ope rationally useful to 01genes such as FLT30 r KITthat encode a separa te entity because it is found to beindicate an unde rlying defec t in myeloid proteins that act ivate signal transduct ion associated with a number of other entities,28 IntroductIOn and overvIew of the ctassuceuoo of the myeloid neoplasms
  • 28. to their g enetic a bno rm alities, but until more data are available, we recommend Class I mutations Class II mutations thai such c ases be classi fied as AM L with m yelodysplasia-related c hanges (multilin- FLT3-ITD PML-RARA eage dysplasia) with the muta tional status FLT3-TKO RUNX1-RUNX1Tl of the gene appended, KIT CBFB-MYH11 Therapy-related myeloid neoplasms (t-AMLJ RAS MLL fusions t·MDS and t-AMlIt-MDSlMPN) remain in PTPN11 the revised classificatio n as a distinct CEBPA subgroup. How ever, most patients who JAK2 NPM11 develop therapy-related neoplasms have received therapy with both alkylating Proliferation and/or Impaired haematopoietic survival advantage; not differentiation and .ub- agents as well as with topo isomerase II inhibitors, so that a division according to affecting differentiation HqUent .poptos~ the type of the rapy is usually not pr actical and not recommended in this revision. It has been argued that 90% or more 01 cases with I-AMLIt-MDS or t-AMl/t-MDSI MPN have c ytog enetic abnormalities similar to those seen in A ML with recur- rent genetic abnormalities or AML with myelodyspiasia-relaled features and could be assigned to those categories. However,its siqrsbcance should not be uoderest- should be evalu ated for FLT3, NPM I and except for patients w ith t-AML who havemated, and it is essential that it be tested CEBPA rnutanons. Cu rrently, however, the inv(16Xp 13.1q22), t(16;16XP13.1;q22)orfor in all cytog enetically normal patients, clinical significance of a mutalion of one t(15 :17Xq22;q 12), in most reported seriesincluding those who demonstrate NPM 1 or more of these genes in the setting of those w ith therapy-rel ated myeloid neo-and CEBPA mutations. mo rpholog ic multilineage dysplasia is not p lasm s have a significantly wor se c lin icalModifications have been made in the clear. Future studies may well prove that outcome Ihan the ir de novo counte rp artssubgroup previously ter med "AM L wi th such cases are better classifie d according with the same genetic abnormalities 136,multilineage ovsprasta." Initially, it wasenvisioned that this g rou p would encom- Table 1.07 Acutemyeloid leukaemia andrelatedmyeloidneoplasms,pass biologically unique AML charac ter-ized by MD$ -like fea tures, in cl ud ing Atutt myeloidIeukaemi,with recurrent gtllllIlIt Ibnormalitlesunfavou rable cytogenetics, a higher lnc t- AMLwith ~8;2 1 )(Q22:Q22): RUNXt-RUNXm oence of ove rex pressfon 01 multidrug AML with inv{16)(p13.1q22} c. (16:16Kpl3.1:q22); CBFB-MYHIt APl with (15;17 )(q22:Q PML-RARA 12);resistance gfycoprotein (AS CS 1 or M DR-1) AMLwitht(9:11){p22:q23}: MLLT3-MLL and an unfavou rable respo nse to therapy. AMl with t(6:9)(p23;Q34): OEK-NUP214Dysplasia in ~50 % of ce lls in tw o or m or e AMl with inv(3KQ 26.2) ort(3:3J(Q21;q26,2); RPN1·EVl l 21Q heematop oienc lineag es w as used as a AML (megakeryoblas with 1 tic) (1;22)(p13; q13): RBMI5-MKL 1 universally-ap plic ab le surrogate m arker Provisional entity:AMl with mutated NPM1 for the myelodysp las ia- re late d featu res . Provisional entity: AML with mutated CEBPA Although the c linical sig nificance of th is Acutemyeloid leukaemia with mye!ody,plilil-related changes grOl.lp has been verified in so me stud ies , Therapy-related myeloid neoplil5m, it has been d isputed in othe rs in w hic h Acutemyeloid leukaemia, no! otherwl$l spec;lrted multivariate anal ysis showed tha t m ultilin - AMLwith minimal diffe!lll1tialiorl AML without maturation eage dyspla sia had no independent sig- AMLwith mallJ"aUon nificance in predi c ting clinical outcome Acute m~ leukaemia wen cytogenetic findings were mc orpo- Acute roonoblasticJmooocytic Ieukaemla rated in tne analysis 1 69, 869, 2356, Acute ~ IeukaelBas 24651. Accordingly, in this revision, this PIse erythroid leukaemia group has been renamed as "A ML with EIythroleukaemia, 8I)1hroidfmyeloid myelodyspl asia- related changes," Pa- Acute megakaryoblas.lic Ieukaetnia Acute basophl1ic IeukaenHa tientsmay be assigned 10this ca tegory if Acute panmyeIosis with myebfibrosis they evolve Irom previously documented Myeloid sarcoma MOS. have specific myelodysplasia- Myeloid proliferations related to Down syndrome related cytogenetic abnormalities. or lastly, Transaent abnormal myelopoiesis if they exhibit mo rphologic mu ltilineage Myeloid leukaemia ISSOCiaIed with Down syndrome dysplasia as def ined above. Pat ients in Blastic plil5maC}loid dendritic u1llll1oplalms Ianer group with a normal karyotype Introduction and overview of lhe classification 01 the myeloid neoplasms 29
  • 29. 227 , 1886~ 2034 , 204 1}, suggesting some classification . However, when the myeloid e) Two p rovi siona l ent ities are added:biological differences between the two sarco ma precedes ev idence of PB or BM AML with mutated NPM1 and AMl withgroups. Fur thermore, the stu dy of ther- invotvement. the irrvnunophenotype should mutated CEBPA. Although not includedapy-related neoplasms may provide valu- be ascertained by flow cytometry and/or as a distinc t entity, examination lor muta-able insig ht into the pat hogenesis of de irrvnunohi stoc hemistry, and the genotype tions of FLT3 is slron gly rec orrwnended innovo d isea se by p rov id ing c lues as to determined by cytogenetic analysis, or in all cytogenetically normal AM L.wh y a few pat ients de ve lop leukae mia the absence of fresh nssue. by FISH o rwher eas most p atients treated with the molecular ana lysis for recurrent g enetic 2 . AM L with mye lodysplasia-relatedsame therapy do not. Therefore, patients abnormalities. Myeloid sarcoma may also changes .with therapy- related neoplasms should be be the initial ind ic atio n 01 relap se in a a) Name changed from · AML with rru lli-de sig nated as suc h, but the specific c y- pat ient previously d iagnosed With AM L or lineage dysp lasia".togenetic abnorma lity shou ld also be may indicate disease progression to a b ) Cases of AML are assig ned to this cat-listed, for example, "therapy-related AML blast phase in pat ients with a pr ior d iag- eg ory if 1) they have a previous history ofwith «s,11}(p22;q23)". nosis of MDS, MDS/MPN o r MPN. MDS and have evol ved to AML , 2) theyAcute myeloid leukaem ia , not otherwise Lastly, the unique featu res of Down syn- have a myelodysp las ia-related cytoge-specified, encompasses those cases that d rome- related myeloid neoplasms has netic abnormality, or 3) if ;<:50% 01cells indo not fu lfil the spec ific criteria of any of been rec og nized in a separate listing that two or more myeloid lineages are dys-the othe r entities. This g roup accounts for incl udes transient abnormal myelopo iesis plastic ,only 25-30% of a ll AM L that are not as- and mye lo id leukaemias (MDS/A ML ) 3. Therapy -related myeloid neoplasms.signed to one of the mo re specific ca te- assoc iate d with Down synd rome. Cases are no longer subcategorized asgories. As more genetic subgroups are "alkyl ating agent related " o r tccoiso-iden tified , the num ber of pa tients that fall Summary of major changes In AML merase tl-intubttor related " or "other",into the AMl , NOS c ateg ories w ill can- 1. AML with recurrent genetic abnorma lities,tmoe to diminish . Of note is that infor ma- a ) AML w ith t(8;2 1)(q22;q22), AMl w ith 4. AM L, NOS.tion used to characterize the subgroups inv( 16}(p 13 .1q 22 ) or I( 16; 16}(p 13. 1;q 22), a) Some c ases previously assigne d to thewithin this c atego ry, suc h as epidemic-- and APL with t(15;17}(q22 ;q 12) are con- subcategory of AMl. NOS as acute ery-logic or clinical out come , is oft en ba sed sidered as AM L regard less of bla st count; throid leukaemia may be re-classihed ason older stud ies tha t inc lud ed patients for all othe rs, b lasts 2: 0% of P8 or of all 2 AML with myelodysplasia-related changeS.now assigned to d ifferent diagnostic ca t- nucleated BM ce lls are req uired . b ) Cases previously ca tegorized as AMLeg or ies. and may not be reliable. Al- b) In API... with1( 15;17)(Q22;q12); FM..-R.AR4, NOS. acute megakaryoblastic leukaemiathou g h the p roposal to collapse th is varia nt RARA uenslocaucos with other should be placed in the appro priatecategory into fewer subgroups has bee n partner ge nes are recognized separately ; ge netic category il they are associa tedmade. the notion that some of these may not all hav e typica l APl featu res a nd With inv(3)( q2 1q26 .2) or t(3:3)(q21 ;q26.2);yet be found to be associated with spe- some have ATRA resistance . RPN1-EVlf, or AM L (megakaryoblastic)c ific genetic or b iologic abnormalities c ) The termer cat egory, AM L with 11q23 with t(1;22)(p 13;q 13); RBM15-MKL 1 .1JcMnargued to maintain this category. (MLL) abnormalities has been re-defined synd rome related cases are excludedMyeloid sarcoma, an extramedullary as -AML with 1(9 ;11)(p22;q23); MLLT3-MLL". from this ca tego ry as well .tumour mass consisting of myeloid blasts, Balanced transtocanons other than thatis inc lud ed in the classifica tion as a d is- involving MLLT3 should be specified in 5 . Myeloid proli ferations related to Downtinc t pa tholog ic entity. How ever, wh en the di agn osis. Ot her abn or malities of syndrome.mye loid sa rco ma occu rs de novo, the MLL , such as partial tande m du p licatio n of New ca tegory to inc or porate trans ientd iagnosis is eq uiva lent to a d iagnosis of MLL should not be placed in this categ ory. abno rmal mye lopoies is as we ll as myeloidAML . and fu rthe r evaluation , including d) Three new cytogenetically delined enti- leukaemia that is Down synd rome relatedgenetic analysis, is necessary to deter- ties are ad ded : AML with t(6;9)(p23;q23); MDS related to Down syndrome is con-mine the approp riate cl assific atio n of the DEK-NUP214, AML with inv(3)(q21q26.2) side red biolog ically identical to AMLleukaemia 117421 When the PB and BM . or t(3;3)(q21 ;q26 .2); RPN1-EV/1; and AMl related to Down syndrome.is concurrently involved by AMl. mese tis- (megakaryoblaslic) with t(1 ;22)(p 13;q 13) ;sues may be used for ana lysis and furthe r RBM15-MKL t.30 Introduction and ove rview of the classification of the myeloid neo plasms
  • 30. , ,. /~ •
  • 31. Chronic myelogenous leukaemia, J W _Vard iman J ,V. Melo BCR-ABL 1 pos it ive M . Bacc arani J . Thiele Definition (WBC) count performed at the time of a for less than 5% of the marrow cells in CP Chronic myelogenous leukaemia (CMl) routine med ic al exa mination is found to and 10% or more indicates disease pro- is a myeloproliferative neoplasm thai be abnormal 1 486 . 755, 1942/. Common gression 14821- Erythro id precu rsors vary originates in an abnormal plur ipotent findi ngs at p resentation inc lude fatigue. but erythroid islan ds are usually reduced bone marrow (8 M) stem cell and is con- wei ght loss, nig ht sweats, splenomegaly in number and size {222 11 . The mega- sistently associated with the BCR-ABL1 and anaemia 1486. 19421 Atypical pre- . karyocytes of CML are smaller than normal fusion gene located in the Philadelphia sentations include marked thrombocytosis and have hypolobated nuclei ("dwarf (Ph) chromosome {154. 1455 . 1607, 18841. unaccompanied by a significantly elevated megakaryocytes"). Althou gh they may be Although the in.tial major finding is neu tro- WBC count as well as initial presentation normal or slightly decreased in number. philic leW<ocytosis, the BCR-ABL 1 is found in BP without a previously detectable C P 40-50% of patients exhib it moderate 10 in all myeloid lineages as well as in some 134 ,486. 17301. In the absence of curative extensive megakaryocytic proliferation lymphOid cells and endothelial cells . The treatment most patients progress from CP 1296.775,22 15.222 1). The initial biopsy natural history 01 untreated CML is bi- or to BP either suddenly or through a transi- tripha sic : an initial indolent ch ronic phase tcoat AP. although some die in AP without (CP) is followed by an accelerated phase progression. The transformed phases are (AP), a b last phase (BP) or both. generally accompanied by worsened per- formance status and by symptoms related ICD-O code 9875/3 to severe anaemia, throm bocytope nia or marked sp lenic enla rgement 17551. Synonyms Ch ronic gr anulocytic leukaemia ; ch ronic Morphology myeloid leukaemia Chronic phase (CP) In CP the peri pheral blood (PB) shows Epid emiology leukocytosis (12-1 000x 1()lI L. median 1 CM L has a wo rldwi de annual inci dence of - 1OQx1CPIL) d ue to neutrop hils in different 1- 2 cases per 100 ,000 po pul ation. The stages of maturation wit h peaks in the disease can occur at any age, but the pe rcent of mye locyt es and seg mented median age at diagnosis is in the 5th and neutrophils 1486, 755, 1164, 1942, 20671 . 6th de cades of life There is a slight male There is no significant dysplasia 11 89 , oreoorno ance 1755, 1053 , 1826 1 . 2458 }. Blasts usua lly account tor less than 2% of the wac 1189, 206 7l. Ab solute Etiology basoph ilia is invariab ly pr esent and Factors p red isposing to CML are unknown. eosinop hilia is common (2067l. Ab solut e Rad iation exp osure has been implica ted monocytosis may be p resent but the frac - in some c ases 1226, 4791. There do es not tion of rnonocvtes is usua lly <3% (189 1. appear to be an inherited di sp osition. except in rare c ases assoc iated with the p 190 BCA -A8 L 1 tsoto rm. in whi ch case Sites of Involvement monoc ytosis is nearly always present and In CP, the leukaemic cens are minimally con fusion with c hronic myelom onocytic invasive and the proliferat ion is la rg ely leukaemia is possib le 114581 The platelet confined to naerocoieuc tissues, prima- co unt usually rang es tram normal to rily b lood . BM an d sple en although the gre ater than 1000 x1()9 and thrombocy- 1L liver may be infiltrated as well . In BP, extra- topeni a is uncommon 119421. The 8 M cel- medullary tissues, including lymph nodes, lular ity is incr eased due to g ranulocytic skin and soft tissues may show infiltration proliferation with a maturation pattern sim- by blasts 1486,1029,15341. ilar to that in the blood 1486, 1534 1 In . F" "i-2.o1 CML. ctvoricphase. A ~ blood SlTlllit" biopsy sections the paratrabecutar Cuff of showing Ieukocy1osis and neu1rophiIic eels at varyI1g Clinical featu res imma ture neutrophile is often 5- 10 cells stages d malnIKn 8asqJIiIia is ~ ttl dyspIasiI Most patients are diagnosed in CP which thick in contrast to the normal 2-3 cell iii ~ B Bone marrow biopsy $IlOw$marked hypeI- usually has an insidious onset. Nearly layer and 1he mallie neutroph~s are situated c:eIIuIanty due to gra nulocytic prolderabon. C The 20-40% of patients are asymptomatic and in the intert rabecutar areas. Eosinophils megaka/yOC)1es in CMl are c:harac:leilsbcaly ~ are diagnosed when a white blood cell may be prominent. Blasts usually account ItIan ~ megakaryocyIes.· 32 Myelop",lile"tive neoplasms
  • 32. stoNs moderate to marked reticulin fibrosis Acce lerated phase (AP) « 100xl()9!L ) unrelated to therapy, 4)in approximately 30% 0 1 cases wh ich In the 3ld ed ition of the WHO Classifica tion clonal cytogenetic evolution oc curringoften correlates with inc reased numbers 110391, it was suggested that the d iagnosis afte r the initial diagnostic karyotype. 5)01 megakaryocytes, larger spleen size of AP could be made if any of the follOwing 20% or more basophils in the per ipheraland reportedly. a worse p rognosis 1 293 , paramete rs were present: 1) persistent or biooo . and 6) 10-19% myeloblasts in the540, 1217.2215. 222 11. Pseudo-Gaucher inc reasing WBC (> 10x1()9!L) and /or per- blood or 8M. Criteria 1- 4 are more likelycells and sea-blue histiocytes are com- s istent or increasing splenomegaly 10 be ass oc iated with transition from CPmooly observed secondary to inc rease d unres ponsive to the rapy, 2) persistent to AP, whereas c riteria 5 and 6 morecell turnover and are de rived rom the mrontocvrose [> 1000xlcYlL) uncontrolled frequently indicate a transition betweenneoplastic clone 1 35. 22271. More than by therapy, 3) pe rsistent thrombocytopen ia AP and SP. Although modifications to80% of patients have sign ifican tly redu cedor no iron-laden macrop hag es 120451.In CP the spleen is enl arge d du e to inliltration of the red pulp co rds by g ranu- locytes in differe nt mat uration sta ges , A similar infiltrate may be seen in the hepatic sinusoids and port al areas.Disease progressionltra nsformedphases in CMtThe recognition of di sea se prog ressionfrom CP to the transfo rmed stages of APand BP is impo rtant for prog nosis andtreatment, but the c linica l and mor pho-logic boundaries between the se stag esolten overlap and the parameters used toidentify them have va ried among di fferentinvestigators [118, 293, 481 , 482, 829 , 1100.194 11 . Furthermore, there are onlyscant data relevant to d isease pr ogre s-sion in the era 01 protein kinase inhibitor(PTKI) therapy. Bone ma rrow c hangesfollowing short and long term PTKI trea t-ment have been extensively stu died showing a reduction 01 g ranulocytic eel- kJlaflly. normalization of megakaryopoiesis, regression of fibrosis and inc rease in Fig. 2.04 CUL dVonicphase, "Pseudo-GaiI:: eels in CML.. A Pseucb-Gauchef cells In COITIllOlIly obsenoed il eccctosis associated with decrease in the marTOW aspIate$ aI pabents WIth CML. B They Ina) also be ~ as loamy or strialed eels in ITIlI"IOW proIilerative act ivity 122191. biopsy sedions. TheseIlisto:)"es are seaJndary " increased celllm::Ner. <We delived from the neopIaslic dln and easily ~ from the &mal rnagakaryoc:yte tt-" rn8f9I"). Chronic myelogenous leukaemia. BCR-ABL I positive 33
  • 33. A ,Fi9. 2.05 Splenomegaly 11 CML A The gross appearara of Itle spleen is solid and uniIonnIy deep red, although areas of inlartt IlI8) appear as IlghIer aIloured regions, 8 TIllred pljp disbibubon of!tie infiltrate usually (XIll1lfesse5 alldobhlefates lhe whil pulp. C The leukaemiC cells are present in!he SInuses as wei asin!he spleniccools of lhe red pulp. ethese criteria have been suggested and observed and may be considered as cases the blasts are Iymphoblasts 1557.different criteria proposed by others pres umptive evidence of AP. although 1138. 1558, 1706. 1913,24541. In BP the[4821. it is recommended tha t the param- these find ing s are almost always associ- blas t lineage may be ob vious morpho log-ete rs liste d abo ve sti ll be conside red as ated with one or more of the othe r c riteria ic ally bu t often the b lasts are p rimitive orevide nce of d isease pr ogression. Whether listed ab ove 1289, 293,15341. The find ing heterogeneous and cytochemical andthey or other parameters, such as drug of lymphoblasts in the blood or ma rrow is immunophenotypic analysis is recom-resistance, necessarily ind ica te shortened unusual in AP and should raise concern mended.survival times or imminent blast nanetor- for lymphoblastic BP 15571. If accumulations of bl asts occupy focalma hon is not c lear in view of the efficacy but significant areas of the 8M , e.q. anof current trea tment strategies, and more Blast phase (BP) entire intenrabecular region, a presump-studies are needed to accurately identify The BP may be d iagnosed when 1) blasts tive dtaqrosrs of BP is warranted , even ifcriteria for AP in the face of PTKI therapy. equal or are greater than 20% of the PB the remainder of the 8M biopsy shows CPOften in AP the BM is hypercellular and WBC or of the nucleated cells 01 the BM, 12891. Immunohistochemical studies lormyelodysplasia is seen 11534, 24581. The or 2) when there is an extramedullary CD34 andlOf terminal deoxynucleotidylincrease in myeloid lineage blasts may be blast proliferation. In approximately 70% transferase (TdT) may help in distinguish-readily appreciated with stains for CD34 of cases. the blast lineage is myeloid and ing such foci of blasts in BP from the lociperformed on the biopsy 116501. large may inc lude neutrophilic . eosinophilic. be- 01 promyelocytes and myelocytes thalclusters or sheets of small , abnormal sophilic . monocytic, megakaryocytic or often are prominent in paratrabecutar andmegakaryocytes associated with marked erythroid blasts or any combination thefeof. perivascular regions during CPoreticu lin or COllagen fibrosis are commonly whereas in approxi ma tely 20-30% of Extramedullary blast proliferations most34 Myeloproliferative neoplasms
  • 34. v- --0 0IIc:orrvnonly present in the sk in. lym ph site of the breakpoint in the BGR gene ALL , small amounts of the p190 transcriptnode, spleen. bone or central nervous may influence the phenotype of the e ns- can be detected in >90% of patientssystem, but can occur anywhere, and may ease 11454) . In CML, the breakpoint in with classical p210 CML as well, due tobe 01 myeloid or lymphoid lineage 110291. BGR is a lmost always in the major break- alternative splicing of the OCR gene 11907, point cluster region M ~8C R . spanning 23061 . However, this breakpoint may alsoIrrm.oopheootyp exons 12-16, (previously known as b1-b5) be seen in rare cases of CML that are d is-The oeutrophils in CP have markedly and an abnormallusion protein, p2 10. is tinctive for having increased numbers ofdecreased neutroph~ alkaline phosphatase formed wh ich has increased tyrosine monocytes and thuscan resemble chronic{16401. In myeloid BP the blas ts may have kinase activity {1454 1. Rarely, the break- myelomonocytic leukaemia 114581.strong. weak or 00 myetoperoxidase point in the eGR gene occurs in the The enhanced tyrosine kinase activity ofactivity but express antigens associated 1J-8CA reg ion , spanning exons 17-20 BCR·ABL 1 is responsible for coosntunvewithgranulocytic, monocytic , megakaryo- (p reviou sly known as C1-C4 ) and a larger activation of several signal transduc tionblastic and/or erythroid differentiation. In fusion prote in, p230, is encoded . Patien ts pathways 15391. This resu lts in thethe majority of c ases the myeloid b lasts with this fusion may demonstrate prominent leukaemic phenotype of CM L ce lls whichwill express one or more lymp ho id an ti- neutrophilic maturation and/orconspicUClUS encompasses deregulated proliferation ,gens as well {557. 1138 , 1558 , 19 13 1. throm bocytosis {1454 , 1685 1. Although red uced adherence to the 8M stroma andMos1 cases of lymphoblastic BP are pre- breaks in the minor breakpoint region, defective apoptotic response to muta-cursor B in origin but cases of T lym pho- m-BCR (BCR exons 1-2) lead s 10 a genic st imuli . The understand ing of theblastic origi n also oc cur p 138 , 1558 , shorter fus ion p rotein (pl90) an d is most abnorma l signaling in CML cells led to 19131. In lymphoblastic BP, one or more freq ue ntly associ ated with Ph positive the design and synthesis of smallmyeloid antigens are co-expressed on the¥nphoblasts in the majority of c ases, Ap -proximately 25% of BP cases fulfill c riteriafor mixed phenotype acute leukaemia(MPAL) 1557. 1138. 1558, 19 131, but theseare considered as exa mp les 01 BP andare different from de novo MPAL,GeneticsAt diagnosis. 90-95% of cases of CM Lhave lt1e characteristic t(9 ;22)(q 34 :q 11,2)reciprocal translocation tha t resu lts in thePh chromosome [der (22q)] 11607. 18841.This translocation fuses sequences of theBCR gene on ch romosome 22 withregions of the ABL 1 gene from c hrom o-some 9 11541. The remaining cases eitherhave variant trensocauons that involve athird or even a fourth chromosome inaddition to ch romo somes 9 and 22 . orneve a cryptic translocation of 9q34 and22<;11.2that canno t be identified by reo-tile cytogenetic ana lys is. In suc h cases,tie BCR-ABL 1 fusion gene is present and F"tg. 2.08 0r.I... myeloid bla ~ ptlase. A ~ l:tlodofl pllientWllh myeIoidbllst phase . Tht ma;onty oftle "*C¥l be detect ed by FISH analysis . AT-PCR l:tlod oats<n blasts. B.C Sheetsof ~ in " bin! ITWTtM bqIsy. D Myeloperolidase del8cllId ImuooOf Southern blot tec hniques 114541. The tvmchei,U1. pIWng ee myetoid lineage of hi blasl P~lIlul. Chronic myelogenous leukaemia, BCR-ABL 1positive 35
  • 35. A Penphetal blood smear. 8 Bone malTOW biopsy C Mam:lw aspirate smear.Fig. 2.10 0Al.. myeloid bIasI phase , in 8Ile~ site . A,8 l~ node biopsy obtained from iI pabent with a tIiStory 01 CML lor 3 ~_ The lymph node ¥d1iteclln isIatgely eIIaoad by a proIrfefatlon 01 medir.Jmkllarge Sized cells. C l~ im~ confirms the myeloid lineage ollhe blasts,molecules that target the tyrosine kina se with point rrutations that prevent the bnding 1657, 1487, 14881, and at the time ofac tivity of BCR -AB L 1, of which imatinib 0 1 the inhibilOf to the kinase domain of transformation 10AP or BP, 80% of patientswas Ihe first to be successfully used to BCR-ABL 1 can lead to d rug resistance, demonstrate cytogenetic changes in ad-treat CML 1616, 6 171 lmatinib competes . p articularly in AP and BP 11103. 23731. ditlOO to the Ph ch romosome, such as anwi th ATP lor b ind ing to me BCR-ABL 1 The second generation compounds nilo- extra Ph, . 8, . 19 , or i(17q). Genes shownkinase domain thus preventing phospho- tmib and d asatinib can circumvent this to be altered in the transformed staqes in-rylation of tyrosine resid ues on its sub- form of d rug failure in the case of most but clude TP53, RB1, MYC, p1 f7"""" {CDKN2Aj,strates, Interruption of the oncogenic not all kinase domain mutations assoc iated RAS, AML 1 and EVil , but their role in lhesig nal in this way is very effective for con- with imatinib resistance 11103, 2373} . transformati on , if any, is currently unknowntrol of the d isease , particularly when used The mol ecu lar ba sis of d isease tran sfor- 18 , 1455 , 14871- The recent introduction 21early in CPo However, the eme rg ence of mation is still large ly unknown . Progression of gen ome -wide expression profiling bysub-c lones of leukaemic prog enitor c ells is usua lly associated w ith clo nal evolu tion mrc roarray tech nolog y has started to reo vea l othe r cand idate genes assoc iated with the ad vanc ed stages , and has also revealed similar gene expression patterns betwee n AP and BP, suggesting that the genetic even ts lead ing to transformation in AP and BP occur in late CP or early AP 11608, 1624 , 18031. Postu lated celt of origin It is curren tly accepted that CML-CP originates from a plu ripotent 8M stem eel. However. disease progression may origi- nate in more corrvn itted precursors lhan previously supposed, as myeloid BP has been repor ted to involve the g ranulOcyte-Fig. 2.11 Fluorescence il SItu hybAckzalion (FISH) with dual color and dual fusion probe on a normal metaphase eel mac rop hage prog enitor pool rather than(A) 8Ild metaphase preparaOOn (8) from a patient witht(9-,Z2)(q34;q11 .2~ AWal alia anddual fusion InInsloc:aIion probeis used (VysisR corporatlon). The ABL I and BCR probes are labeled with SpectrumOrange and SpectrumGreen the naerroooletc stem cell pool 114741.respecIJYeIy. In JlOfmllI eels (A) two orange Signa represenbng the ABL 1 gene al 9q3.4 and two green SIgnals repre- ls Whether the same applies to lymphoid BPsenting the BC at 22(111.2are &hown. In the pall&nls CMl cell (8) one orange (JlOfmllI 9q34), onegreen (normal R s is not know n,22q11.2) andtwo orangeJgteen(yelOw) signals, repl"esenOOg derivative 9q3.4 and 22q11 ,2, respedively, ar detected. e36 Mye loproliferative neoplasms
  • 36. AlP-bind ing com etitors m t?9;22)(q34 ;q11.2) L- l ---.J BCR.ABL1 813a2 .1402 p210A Brig. 2.1 2 ... SC1lemabc representabDn of !he U:9:22) chromosomallranslocabon, me fusion mRNA ~ encoded by !he BCR..-&.1 tl)trid gene geoeqted in !he 22q. orFIlIacletiIlia (PIli chi OliiO«Jmll , and hi nnslated BCR-ABL1 kl5ion protOO, ...nose oncogenic ptqlllrties Ie/y pllIlIiIdy on ts conslllUOVely actrvaled tyrosne U1ase en:xlded byties..:~ I ISH1)domain illicatedby ltle red Orde. Some of It1e oltlef ~ UlcWlaI donIaIS CQ1tnlluted by tie BCR andABLl pcnons oIlhe Oi iCClPi oceifl n sIlowfl.These n 1Ile dMnensaliOn domain (00): Vl n wtlich is !tie allloptlosphoryllion s<1e crucial lor binding to 008-2; the ptIospho-Ser and -Thr SH-binding dorrI<Wl; a regionturdogaIs tI Rho guarlIdne ru:Ieoticle exet.ange laclots (Rho-GE.F): ee ABll regoJa1o"y SH3 and SH2 domains; Y412 as !he map Slt8 r:I ~ wiltlillhe StUIrNse dcrnarI; ru::i8ar kx:att:alitw, J9IaIs (tt.S) and lhe DNA- and adn-I:imng danains.. B Mectllnsm 01 adIion 01 acR-A8I..l yrtliW1e kNse ~ M1ereas h physdogicaItning rJA III its poDelllbn BCR-ABLllO phosphorylate seIeded tyrosWle residues onrts SI.tIslrales (left <iagam). a synlheIicATP rrmc such lIS inalinlb fits t1ls poct.et TPIiaopm),lluliXles nol prOYide Ihe esseoIiaI phosphate ~ lO be transfem!d k11he SI.tIslraIe Thedownstream d1aIn 01 reactions is lhenhaAed because,lfIIiltI irs tyrosines illhe t.. ,~ form. ee subslrate does not assume the necessary ronJoonabon 10erlSlH associabon WIlh itS efleclor.~ and predictive factors and donor ty pe 1116 , 828, 20221. Thre e pres ence or abse nce of m ye lofib rosisBased on historical data prior to any pr ognosl ic models ba sed on baseline 1292 , 293, 12 17, 12 181. Pretra nsplanteffective therapy, median survival times in pr ognostic variables including age , myelof ibrosis ha s been reported to beCML ranged bet ween 2-3 years {7671_ spleen size, p late let count , the percent- associat ed wit h a delayed or failure ofWith conventional c hem othe rapy (bus ul- age of mveiobrasts in PB as well as the naematoooenc reconstitution 129 22071. 3,fan, Hydroxycarbami de) me dian survival percentage of basophils and eosinopnns How ever, in the current era of PTKIwas about 4 years, but progression to AP in the PB allowed the c alc ulation of rela - therapy, the most important prognosti cand BP was only slightly delayed w ith 10- tive risk, hence of the life expectancy, of ind icator is the response to treatment atyear overall survival (OS) less than 10% patients treated with conventional chemo- the haematologic , cytogenet ic and mo-1767, 1948, 2022). Interfe ron-u -based therap y an d inte rferon 1905, 1101 , 2044 1 lecular level 1116/· Cu rrently the comple teregimes delayed prog res sion signili- and w ith im atinib { 116, 6 15), b ut not those cytogenetic response rate to ima tin ib iscarttly, with median survival of approxi- treated wi th all ogene ic stem ce ll tra ns- 70-90%, with a 5-year progression freemately 6 years and to-yea r OS of - 25% p lant. Som e stud ies have show n that the survival and OS between 80 -95% 1116,1115l. With allogenic stem ceutransotant. p redictive va lues of these models can be 61511O-year OS ranges between 10 and 70%, fur ther improved by the inclusion of mor-depending on d isease phase, patien t age phologic parameters, particularl y the Chrooc myelogenous leu kaemia, BCR-A BL 1 po sitive 37
  • 37. Chronic neutrophilic leukaemia B.J . Bain RD. Bru nning JW. Vardiman J . ThieleDefinitionChronic neutrophilic leuk aemia (CNL) is arare myeloproliferative disease . cha rac-terized by susta ined peripheral bloOd (PB)neut rop hilia. bone marrow (8M) hypercel-lulanty d ue to neutrophilic granu locyte pro-liferation. and hepatosplenomegaly. Thereis no Philadelphia (Ph) chromosome orBCR·ABL 11usion gene, The diagnosis reoquires exc lusion of reac tive neutrophil iaand other myeloproliferative neoplasms,ICD.Q cod e 996313Epidem iolog yThe true incidence 01 CNL is unknown ,but only about 150 cases have beenreported. In one study 01 660 cases ofchronic leu kaemias of myeloid origin. nota singlecase 01 CNL was observed 1 20031.CNL gene rally affects olde r adults. but .. . :t Ihas also been reported in adolescents Fig. 2.13 Ovtnc newophIc ~ _ A The neutrophiia dIatac:IeristIc oIltie ~ t*:xx1 il CNL B The. .1909, 2474, 2504}. The sex distflbulion is granUatiolllXlr!JTllldy obsetoed. Reproduced from Anastasi and ~ (3SAJ. C The bone rnatfOW asprDt SI!Wnearly equal 1231 . 640, 2474, 25041. der!lcmIra neutrophil proWerabOn from myebcytes to ~ forms Mlh toO: granu/abOn, 1M no olIW" tes s9ificant abnormaibes. D The bone marrow biopsy specimen is hyperceWar, showing a markedly eIevMldEtiology myeIoicI:erylM:lid ratio WI!h increased IIJrmers of nNrophk, partK:tarly maturesegmented bms.The cause of CNL is not known. In up to20% of reported c ases, the neutrophilia infil trates 12257. 2474 . 2504 1 How ever, . are almost never observed in the bloodwa s associated with an und er ly ing neo- any tissue may be infiltrated by the rectro- The neutrophils often ap pear toxic . withplasm , most usua lly multiple my e loma phils 1 2257 , 2474, 25041. abnorma l, coa rse granules, but they may1355, 58 4, 20761 To dale, no cases of . also a ppear normal. Neutrop hil dysplasiaCNL as sociated with myeloma have been Clinical features is not present. Red blood ce ll and plateletrep orted in wh ich a clonal c hromosomal The most constant c linical feature reported morphology is usually normal. The 8Mabnormal ity o r evid enc e of cronauty by is sp lenome ga ly. whi c h may be sympto- b iop sy shows hypercel lular ity w ith neu-molecular tec hniques has been co nvinc - matic . Hep atomeg aly is usu ally present trophilic p roliferat ion. The myeloid:e ry-ingly d emons trated in the neutroonns as we lt 12474 , 2504 1 A history of b leed ing throid rat io may reac h 20 : 1 or greate r120771 II is thus likely that most cases of . from mu cocutaneous surfaces or from the Myelo blasts and p rom yeiocytes are notCNL associated w ith mye lom a are not gastrointestinal tract is reported in 25-30% inc reased in percentag e at the time 01 di-autonomous prolif erations of the neuuo- of patients 1909, 25041. Gout and pruri tus agnosis, but the percent of mvelocvtee --phi ls , but are secondary to abnorma l are other possi ble symptoms 1 2504 1 . and mature neutrophils is inc reased. Ery -cvtokme release from the neoplastic throid and megakaryocytic prol ifera tionplasma cells or othe r cells regulated by may also occur 1231, 24741. Sig nific antthe plasma cell population . The same The PB smear shows neu trophilia w ith a dysplasia is not present in any 01 the cellmay be true of C NL associated with other wh ite b lood celt count ~25x l ()9/L.. The lineages and, if found , another diag nosis.neoplasms. However it should be noted , neutrop hils are usuatty segmented, b ut such as atypical chronic myel oidthat evolution to acute myeloid leukaemia there may be a substantial increase in leukaemia . should be considered (See(A ML) occurred in one pat ien t with CNL band for ms as we lt. In almost alt cases, Chapter 4). Retic ulin fibros is is uncom-associated with multip le my eloma {5841 . neutrophil precursors (pn::rnyeIocytes, mye- mon 1231, 640 , 2474, 25041. In view of the iocytes. metemyetocytes) account for reported frequency of CNL in associationSites of involvement fewe r than 5% of Ihe white cells, but oc - with multip le myeloma, the BM should beThe PB and BM are always involved, and casionally, they may account f()( ~p to 10% examined for evi dence of a pl asma ceuthe splee n and liver usually show leukaemic 1 ,640 , 909 , 2474. 25041. Myeloblasts 231 neoplasm 1355, 584, 2076, 20771. If plasma38 Myeloprol iferat ive neoplasms
  • 38. cell abnormalities are p resent, clona lity 01 Table 2.01 Diagnostc criteria lor chronic neu troph~ iC Ieu ~aemia.the neutrophil lineage should be sup- Peripheral blood leukocytosis, wac <:25xW/Lported by c ytog enetic or molecular tec h- 5e9meflted neutrophils andband folms Bftl >80% of wtlite bloodceasniques be fore making a ImmatlKEl granu~es (promyelocytes, myebcytes, metamyelocytes) <10%ofwtllte bloodcellsdiagnosis of CNL. Splenomegaly and Myeiotllasts<1 %of It11ite blood cellshepatomegaly result from tissue inliltration 2. HyperceftlJar bone matTllW biopsyby the neutrop hils. In the spleen , the infil- Neutrophilicvanuloc)1es increased IIl pen;enlage andnumbertrate is mainly confined 1 the red pulp; in 0 Myeloblasts <5% 01 rWeated ITCIlltIIIf cetIs!he liver. the sinusoids, portal areas or NeutmplVliC maluration paneronormalboth, may be infutrated 1 2474, 25041. Megaka ~ normal or left shifted 3. HepatosplenomegalyCyll(:hen>stryThe neutrophil alkaline phosphatase score No_.. . . 4 No ideflt!f.able caJ5e lorptrysioIogic neutrophika or. if presanl, denw:lnslration 01 donaIiIy ofmyeloid eelsIS usually norma l or inc reased. but no by cytogenelic or molllo.I* studiesOCher cvtocoencarabl"l()(mahty has been Noinfecbous or J1lIarnmaIory JlItlC8SSfepor1ed 1 2504 1. 909. 5 NoPtlitadelphia cMlmo5ome or BCR-ABL 1 Mlon gene""""""CytogenetIC studies are ooemat in nearly00% 01 patients. In the remaining patients, 6. 7. No ~ d PDGFRIo , PDGFRB or FGFR1 No ~ of polycy1tlaenia vera. ptiTlaty AI)elofibmsis or essential ~clonal karyotypic abnormalities mayinclude +8, +9 . +2 1, del(2Oq ), del (1 1q) 8. Noevidence 01 a myebcIysplaSllC ~ or a myeIodyspIasIicImyeloproleraliw neop(asmsandde~12pl l 566. 640 , 736, 1415, 24661 . No gtafUcqtc dysplasia No myelodysplaslic changes IIl olher myeloid hagesClonal cytogenetic abnormalilies may MonocyIes <hl O"ILappear during the cou rse of the disease .There is noPh chromosome Of BCR-ABL 1fusion gene. A vana nt of chronic myel-ogenous leukaemia, BCR·ABL 1 positive and 1(15; 19)(q13:P13.3), suggesling the from 6 months 1 more than 20 years. 0(CML) has been repo rted that demon- possibility of an unident ified fusion gene Usually the neutrophilia is p rog ressive.stratesperipheral blOOd neutrophil ia stm- in some cases 1433 J. and anaemia and thrombocytopenia mayilar to that seen in CNL 1168 51 In such . ensue. The development of myelodysplasticcases, a variant BCR-ABL1 fusion protein , Postulated cell of origi n features may signal a translor mation ofp230, is found. Cases with this molec ular Cell of origin is unknown. It is most likely the disease to AML, which has been re-variant of the BCR·ABL 1 fusion gene a BM stem cell with limited lineage oo- ported in some patients 1 909, 2504 1 It is . should be considered as CMl , not CNL. ten tiaI 1736, 2466 1. not clear whether the transformation was Occasional patients with a JAK2 rnutation relate d to previous cytotoxic therapy in have been reported [1083, 14351and this Prognosis and predictive fac tors the cases rep orted. bassometimes been homozygous 110831. Although generally regarded as a slowly Ccrnplete cytogenetic remission with ima- prog ressiv e disord er, the survival of tnib was reported in a patient with CNl pa tients wi th CNl is variable , ran gin g Chronic neutrophrlic leukaemia 39
  • 39. Polycythaemia vera J. Thiele H ,M , Kvasnicka A,Orazi A TeHeri G , 8irgegardDefinitionPoiycvtbaemra vera (PV) is a chronic Evolution _ Manifestation - - - - - - -•• Transformationmyeloproliferative neoplasm (MPN) char- Post -polycythaemcacterized by increased red blood cell myeIokl metaplasiaproduction independent of the mechanisms (post-PV MF) ...10"Jl,,;15Mi 1that normally regu late erythropoiesis. ....21 Idl!!!9-U- . - -_ _ 20 %Virtually all pat ients carry the somaticga in-ol-lunction mutation 01 lhe Janus 2kinase gene, JAK2 V617F or anothe rfunctionally similar JAK2 mutation thairesults in proliferation not only 01 theerythroid lineage but of the granulocytesand megakaryocytes as well , t.e "pan- t ~.Iy 1myelosi s". Three phase s 01 PV may definite increase In L.._ < 10 %be recognized : (1) a prOdromal, pre- red cell mass Post-PV MF WIthpo lycythaemic phase c harac terized by biasbc transformationborderline to only mild erythrocytosis; (2)an overt poIycythaemic phase. associated I II 11with a significantly increased red cell mass ; Tennin.J1 sageand (3 ) a "spent" or post-oovcvtnaemicmyelofibrosis phase (post-Pv MF) in Fig. 2.14 SdJematic presentabOn of ee 8YOIuliOn of 1hedisease process ., ~ vera.which cvtooeruas. including anaemia . areassociated with ineffective haemato-poese. bone marrow (8M) fibrosis. extra-medullary haematoooesrs (EMH) . and Etiolog y Sites of involv eme nthypersplenism, The natural progression The underlying cause is unknown in most The blood and 8M are the major sites 01of PV also includes a low incidence of cases. A genetic predisposition has been involvement, but the spleen and fiver areevolution to a myelodysplastic/pre- reported in some famil ies 11778 , 20321. also affected and are the major sites ofleukaemic phase and/or to acute leukaemia Ionizing rad iation and occupational EMH in the later stages, However, any(AML). All causes of secondary eryth ro- expo sure to toxins have been suggested organ can be damaged as a resultcytosis, inheritab le po lycythaemia and as po ssib le causes in occasional pa tients of the vascular co nsequences of theothe r MPN mus t be excluded. The d iag- 1312}. increased red cel l mass .nosis requires integration of c linica l, labo-ratory and 8M histolog ica l features asoutlined in Tab le 2,02 . Tab 2,02 Diagnosticcriteria lor poI~emia vera (PV). Diagnosis requires the presence 01 bottl major criteria and leICD-Ocode 9950/3 onemM criteriOn or he presence of the firstmajor cri telorl togeth&r with two minor criteria.SynonymPolycythaemia rubr a vera, Majorcriteria t. Haemoglobin >18.5gJdL., men, 16,5g!<ll in IoOfTl8l1 orother evidence of eceeseo red cell voll,lTlEl 2. Preserce of JAK2 V617F or otnerfunctionaly slnVlar mutiltion sudl as JAKZe_on 12 rllI.ltalion IEpidem iology Minor criteriaThe reported annual incidence of PV t . Bone marrow biopsy shoWing hypercellularily lor ageWIth lJirIeage growttl (panmyelosis) wiltl prrITWIefllincreases with advanced age and varies erytIvoid, granulocytic aodmegakaryocytJc proMerabonfrom 0.710 2.6 per 100 000 inhabitants in 2. serum erylhlClPClien levelbelowthe reIerenc:e range lor normalEurope and North America. but is muchIavver in Japan 110591. Most reports indicate 3. EIIOOgenous eryttvoid colony Iormabon IIl VIttoa slig ht male predominance, with the M :F • Haemoglobin Of haematoall >99th pertentile of rneIIlod-speofJ reference range lor age. sex, albtude ofratio rang ing from 1- 2:1 ISO. 1389 1. The resideool a hael,qJobiI. >11 gill. 10 men. 15 Wdl in women • assoaaled WIth a doI:menled iIfld sustanedmedian age at d iag nosis is 60 years . and Mease of alleasl 2 gldL from an indMduals baseline value Ilal tarl nol be attnbuted 10 correctlOn 01 irOnp atients you ng er than 20 years old are defDency, or lll&vated red c:eI flIa$$ >25% llbove mun normal predicIer:l valueonly rarely reported 117001.40 Myeloproliferative neoplasms
  • 40. Clinical features The major symptoms of PV are related to hypertension or vascular abnormalities causedby the increased red cell mass, In nearly 20% of patients an episode of venous or arterial thrombosis, such as deep vein thrombosis, myocardial is- chaemia or stroke, is documented in the medical history lSOI and may be the first manifestation of Pl/lSO, 197, 1389.20711. Mesenteric, portal or splenic vein throm- Fig. 2.15 Fdycylhaemiaveta, ~stage. A I.WcIy hyperc:eWa bone IfilIJOIIWsIoIrorIga ~01 bosis and the Budd-Chiari syndrome large megakaryocytes in ee bone mafIOW secUon. B Many large ¥ld gianttlyperIobuIated ( ET~ ke) megak¥yotytes should always lead to coosideration of PI/ in a paleIIl dilic:ally mrrickJng ET, because 01 a platelettxUlt in excess 0I 10D0xlO1t- Note ee my dIy inaeased asanIJlderlying cause and may precede ~ lnf ef)tt"ropoiesi (panmyelosis), beUerdlImDl ostraIed by ~ esterase f9ClCtiOrL the onset 01 an overt polycythaemic phase ISO, 2701. Headache, dizziness. visual disturbances and paraesmeses the morphological findings are of sufficienl normochrcmie, normocytic red blood cells. are major complaints, and pruntus. ery- specificity to allow distinction of PV from If iron deficiency due to bleeding is pres- thromelalgia and gout ere also common. secondary poIycythaemla as well as other ent. the red cells may be hypOchromic In the full-blown polycythaemic stage subtypes of MPN 122031, and microcytic. Neutroptufia and rarely physical findings usually include plethora basophilia may be present. Occasional and palpable splenomegaly in 70% and Pre-polycythaem ic phase and irrmature granulocytes may be detectable hepatomegaly in 40% 01 patients 11445, overt poIycythaemia in the overt polycyttlaemic phase, but cir- 20711. Generally, in the pre-polycythaemic and culating blas ts are generally not observed , Clinical laboratory studies that aid in polycythaemic phases of PV the major Because of prominent thrombocytosis, up confirmation 01 the diagnosis of PV features in the peripheral blood (Pal and to 15% of cases of early phase PV includ subnormal erythropoietin (EPO) e 8 M are attributable to effective proliferalion may clinically mimic essential thronbo- levels [223. 15271. endogenous erythroid in the erythroid , granulocytic and megakary- cvthaerma (Ell 122101 but such cases c:oklny (EEC) formation 15951. and oetectoo ocytic lineages, Le. there is pannweosrs. eventually evolve into an overtly poly- at the JAK2 V617F or functionally similar The PB shows a mild to overt excess of cvmaemc stage 11047, 2007, 22101. mutations, e.q. JAK2exon 12 mutations 11 981,2168. 21771. Occasionally. patients may present with clinical symptoms suggestive of PV b ut WIth a haemoglobin level and/or red cell volume not sufficiently e levated to sub- stantiate the d iagnosis. Such patients may be in the pre-oovcvtbaemrc phase, wtlich was previously refe rred to by some authors as "latent PV or as p ure id io- pathic erythrocytosis" 1197,1559, 1715, 1697,2224), The detection of a sub normal EPO level, a JAK2V617F or funct ionally similar mutation andlor abnormal EEC lcmaton. in combination with the typ ical morphologic features described below, will allow the diagnosis of this phase of PV; these features are not found in secondary or spurious polycythaemia. The ore-ooivcvtnaemc phase may be expected to become overtly poIycythaemic at a later time. Maphology The morphological lind lngs in BM biopsy specimens at patients with PV must al- ways be correlated with other clinical and taboratory fmd ings in order to firmly es- tablish the diagnosis 121771. However, eYen n the earty pre-po/ycyttlaemi stage PoIycythaemia vera 41.
  • 41. FIg. 2.11 AcuteIeukaenilWl poIycyth8emia WlflI . Blood~ from a pabenl M1h. ~ Ilist:Iy of PII.The patient had been treated with a/kyIabng agents!bing !he poIycyIhaemic stage. The blasts eeeseeeC013. C033. C0117 alld C03-f. and had a compleJ.......karyotype. COf1SISlenl wrIh Illerapy-related aalte myeloidBone marrow cellular ity has been reported They typically tend to lo rm loose c lusters well as the distinction from reactive ery-to range from 35-100%, with a median or to lie close to the bone trabeculae, and throcytosis and thrombocytosis is feasiblecellularity of about 80% [641 1 but c har- , often show a significant degree 01 pleo- {2211 , 22221. Reticulin stains will show aacteristically the BM biopsy is hyperceuu- morphism with a mixture of different sizes . normal reticulin libre network in aboutlar for the pa tients age. A finding that is The major ity of the megakaryocytes 80% 01 patients . but the remainder displayespecially noteworthy is increased ce llu- exhibit normally folded or deeply lobulated inc reased reticulin and even borderline 10larity in the subcortical marrow space, an nuclei, and usually lack significant cytolog- mild collagen fib rosis {297 , 641 , 775,area which is nor mally nyooceuurar (775 , ica l abnormalit ies, alt hough a minori ty 1189,221 1] de pen d ing on the stage 012203] Panmyelosis accounts for the in- show bul bous nucle i and othe r nuclear disease at first dia gnosis, Reactive nodularc reased ce llularity b ut an increase in the ab norma lities, pa rticularly when assoc i- lymp hoid agg regates are found in up tonumbe rs of e ryth roid pr ecursors and of ate d with a minor incr ease in ret icu lin 20% of cases {22031. Sta ina ble iron ismeg akary oc ytes is often most promin ent {22 111. When taking the c ha racte ristic lack ing in the 8M as p irate and biopsy{641, 775, 22031. Erythropoiesis is normo- histological pattern of PV into account, specimens in mo re than 95% of the casesbl astic, and granulopoiesis is mor p ho- d iscr imination of PV from ET and PMF as 1641, 22221 .log ica lly no rmal. The pe rcentage ofmyeloblas ts is not increased. Mega karyo- Tabl.2.03 Diagooslicaileria fOf postiJOlycythaemic myelofibrosis (posl-PV MF )cvtes are increased in number. particu-larly in cases with an excess of platelets, Required criteriaand display characteristic morphological 1. Documentation ofa previous diagnosis ofMiQ.defined PVabnormalities, such as hyperlobated 2, Bone mallOlll1ibl"os4s grade 2-3 (000-3 $C8Ie) orgr-ade 3-4 (000- 4 scale)nuclei, even in the early phase of thedisease , The presence 01 the panmyelo- Additional criteria (2 art rtquiredjsis, which although less prominent in the 1. Anaemia Of sustained km of ei1hef pl1Iebotomy r~ the abseoce of ~ therapy)orcytoreduc:M lrealmenl requilKnent b~spre-poivcvtnaenc than in the overt poly-cythaemic phase, is nevertheless de- 2, Leukoel)1hroblaslic penpheral blood picbQtectable and helps to distinguish early PV 3. Incteasll1g spIenornegllIy defIOlld as .rther aninaeasein palpable SPleoomegaIy of >S an from baseIintfrom ET whi ch it may otherwise resemble , ldistanee from the left costal marg.n) Of Iht 1pp&afaflC8 of newly palpable spleoomegalyclinically 1221 01 As in the pre-pdycythaefr · 4 Development of >1 of 3 consblulional symploms: >1 0%weighlloss il611lC111tts, iWJhI sweats. 6phase, megakaryocytes seen in the unexplained IeoeI (>31.S C)poIycythaemic stag e 01 PV are clearlydi st inguishable from those seen in ET.42 MyeloproliferatIve neoplasms
  • 42. "Spent phase"and post·polycythaemicmyelofibrosis (oost-Pv MF)During the later phases of PV, e rythro-poiesis progressively decreases. As aconsequence, the red blood cell massnormalizes and then decreases, and thespleen further enlarges. Usually theseChanges are accompanied by correspon-ding 8M aneranons 1641 . 20711. The mostcommon pattern of disease progressionis posf-Pv MF accompanied by myeloidmetaplasia which is characterized by aIeukoerythroblastic PB smear, poikilocyioss wil h teard rop-shaped red bloodcells. and splenomegaly due to EMH , asdefined in Table 203 {143A). The mor-phological hallmark of th is slage of thedisease is overt reticulin aOO collagenfbrosisofthe BM 1641 . 775 , 2203, 22221,The CelkJarity varies in this terminal stage.tu: hy1:loceIIular specimens are coreroo. Fig. 2.19 ~ Yllla, ~ rnyelofbosis (pos&-PV MF) and"¥lbd metaplasia , splerJedoi"rCUsters of megakaryocytes, olten with specinen. The splenic enlarvement in the ~ ptIase isdue IlIMlIy b eJb"ameOJlary Ilaema!DpoIesishyperchromatic and very dysmorphic !hat Cll:X:ln II1 It1e splenic sftlses , as wei 11$Iibrosis.-.d lll1trapmenl d platelets and tIaernalopoieli eels II1lhe splenicnuclei, are prominent Eryth ropoiesis and coosgranulopoiesis are decreased in amount.and are sometimes foun d . along withmegakaryocytes, lying within dila ted mar- iower freq uencvltea. 1044 ,1 186 , 12881. Postulated cell of ori gi nrcw srcsocs 12203 1. Osteosclerosis may The mutation occurs in a haematopoielic Heemetopoteuc stem cel l.also occur 1 1, 775 1 The splenic en- 64 , stem cell , and is found in all of thelargement is a consequence of EMH , myeloid lineages. Hence cells that utilize Prog nosi s and pred ictive fact ors....nich is characterized by the presence of JAK2 kinase in the intr acellular signaling With currently available treatment, medianerythroid. granu locylic and megakary- path way may be hyp ersen sitive to g rowth survival li mes > 10 ye ars are commonlyccvnc elements in the splenic sinuses fa ct ors a nd other cvtokmes. inc lud ing repor ted {SO, 1215 , 1548,2071/ . although and cords of Billrot h. An increase in the EPO . A fun ct ionally similar mutat io n in controversy persists about the risk factors number of immature cells may be ob- exon 12 of JAK2 has also been reported other than olde r age {1215, 1389, 17021 . served in these stages, butme finding of 11981/. so that virtually all patient s with PV Most p atients d ie from thrombosis or ) 10% blasts in the PB or 8 M or the pre s- have a JAK2 aber ration , St ill, no ge ne tic haemorrhage , but up to 20% succumb to ence of signific ant my e lodysp lasia is defect enti rely specif ic to PV has been myelodysplasia or acute mye loid leukaemia unusual, and mosl likely sig nals tran sfor- ide ntified . At diagnosis, c yto ge ne tic ISO, 1389, 207 11, mation to an acce lerated phase and/or a ab normal ities are detectab le in ab out The factors tha t p red ict the risk of throm- m yelodysplastic synd rome (MD S), Cases 20% of pa t ients. The mo st c ommon bo sis or haemorrhage are not well inwhich 20% or more blasts are found are rec urring abnormalities inc lude +8, +9, d efined 11389, 1700,20711, The incid encecnsoerec AML 117 2071, 2203, 2222). 01, del(20Q), de l( 13q) and de l{9p) : some- of MDS and ac ute leukaemic transforma- times +8 and +9 are found tog ether 142, tion is only 2-3% in patients who hav e not""""phenotype 2394/. There is no Philade lphi a c hromo- been treated with cy totoxic agents , butNo abnormal phenotype has been reo some or BCR-ABL 1 fusi on g ene . The se increases to 10% or more follow ing"",eo c hromosomal ab normalities are seen with ce rtai n types of c hemot hera py {704 , increasi ng frequency with d isea se pro- 1389 , 1548 , 170 1, 1702 1_Goo" gression and in near ly 80-90% of thoseThe mosf frequent genetic ab normality in w ith post-PV MF 1421, Almost 100 % o fPV is the somatic qam-ot-tuncnon mut a- those wh o develop MDS or AMl havetoo JAK2 V617F. Altho ug h il occurs in cyt ogenetic abnormalities. inclu ding those> of patients with PV, it is not specific 95% commonly o bserved in the rapy-relatedand is found in other MPN as well. but in MD S and AMl (See Chapter 6 ). PoIycythaemlCl vera 43
  • 43. Primary myelofibrosis J . Thiele H M . Kvasnicka A. Tefferi G. Barosi A. Orazi JW. Vardi manDefinition ICD-O code 9961 /3 in yo ung chil d ren have been reportedPrimary myelofibrosis (PMF) 11464 1 is a How often this represents an MPN is ~clonal myeloproliferative neoplasm (MPN) Synonyms known. but at least some cases appear 10characterized by a proliferation of pre- Chronic idiopathic myelofibros is (CIMF); represent an autoscmal recessive imenteddominantly megakaryocytes and granulo- Agnogenic myeloid metaplasia (A MM); oondilioo 118731· In oee- families with acytes in the bone marrow (8M) that in fully Myelofib rosiS/scl erosis with myeloid meta- somewhat later age of onset . the leal1.Xesdeveloped d isease is associated with plasia (MMM) ; Id iopathic myelofibrosis . havebeen consistent withan MPN, suggest-reactive deposition of fibrous connec tive ing a familial predisposition to PMF 13691.tissue and with extramedul lary haema- Epidemiologytopoiesis (EM H) . There is a step wise evo- The overt fibrotic pha se is estimated to Sites of involveme ntlution from an initial prefibrotic phase oc cur at 0.5- 1,5 per 100 000 persons per Blood and BM are always invo lved. In the121771 cha rac terized b y a hypercell ular year {1060,21671. It occur s most C()fTVTK)ll1y later stages of the d isease , EMH (alsoBM wit h absent or minimal reticulin fibrosis in the sixth 10 seventh decade of life, and kno wn as myeloid metaplasia) becomesto a fibrotic phase with marked reticulin both sexes are nearty equally affected prominent, in particular in the spleenor collagen ubrosrs in lhe 8M and often 121671. Children are rarely affected 136n 117731. In the initial stages. randomly dis-osteosclerosis. This fibrot ic stage of PMF tnbcted C034+ prOlJenitors are slightly in-is characterized by ieukoervtbrobiastosis Etiology creased in the 8 M. but not in thein the booo witll teardrop-shaped red cel ls. Exposure to benzene or ionizing radi ation pe ripheral b lood {PBl· Only in the tateand by hepatome galy and sp lenomegaly has been documented in some cases stag es they ap pear in large numbers pe-(Tabl e 2,0 4 ). {5881 Rare familial c ases of 8 M fibrosis riphe rally (1592, 22091 This increase of CD3 4 + ce lls in the PB is a ph enomenon large ly restric ted to overt PMF and is not seen in non-fib rotic po lycythaemia vera fibrosis: <iagnosi requires meeting all 3 mator and2 miroof crileriaTable 2.114 Diagnos1ic crilefialor primary myelo s (PV) or essential thrombocythaemia (ETl MaiOI eritltria 141 ,1 45,17031 . It has been postulated t . Presence d ~ ........... 1 n atypiI" usuaIylaXllTlpalied byllitlerreIla*l inlier a:tagen ~ , that EMH is a consequence ot me pecu- " nile absenat d sig1Icat /W)Jin Iibrosi:s, tle ~ chatgesIlLISI be llCClJIllliDed by al 1lcJeaged liar ability of the spleen to sequestrate the numerous ci rculating CD34+ cells 122081 . bone ITI8fTOWcelIularrty characlenzlld by granuIol:yIic pn:jferabDn and often deaea:Sed erythn;lpooesis ~ e. p!VftlroIic ceItEr-pllase disease ). Liver. lymph nodes. kidney ad renal gland. dura mater, gastrointestinal tract, lung 2. Not meeting WHO Criteria lor poIy<:ythaemia~. BCR·ABLt+ chronic myeIogeoous leukaemia. and ple ura. b reast skin and sott tissues myelodysplaslic syndrome.fJ( other myejoid neoplasms are other possible sites of EMH 1216n 3. Demonstration of JAK2 V6t7F or other donal mark (e,g. MPL W515K!L), er " in the absence 01 a clonal marker. 00 evidence lhatlhe bone marrow fibrosis et otherc:Nlnges aresecondary Clinical featu res Up to 30% of patients are asymptomatic kl mecoon.autorr1rrone dison:ler r:K0lIlerchronic I1ftarnnatory tallIIJon hairyC8lI ~ et OCher IyrnJ:tMjd at the time of diagnosis and are d iscov- neoplasm, metasta1ic mal9ancy. et klxiC (etvonic) myeIopaltlies" ered by octcctco of splenomegaly during Minor aiteril a routine physical examination or when a 1 .l~ routine blood count discloses anaemia . 2. Increase on serum lactate deIlydrogerIase level leukocytosis and/or thrombocytosis. Less 3, AraemIa. commonly. the dia gnosis results from , S""""""",, d isc over y of une xplained teukoervmro- btastosis or an increased lactate dehydro- I Small to largemegakaryocyteswith an aberrant nuc learlcytoplasmic ratiO and hyperchromatic, bulbous, or g enase (LDH) {366 . 2 16 7, 2 1771. In the irregularly loIded nuclei and dense clustering initial p refib rol ic phase of PMF. the only b Requires !he lailure 01 ironrnpiacemenllherap)to increa sehaemoglobin level 10 tile potycythaem~ vera range in the presence 01 decfeased serum fembn. ExckJsion of poIycylhaemia vera is based on haemoglobin find ing may be marked th rombocytosis and haematocrit levels.n red eel massmeasurement is not required, mimicking ET 12177, 220 11. Therefore. a < Requns the absence oIBCR.ABL.1 , sustained thrombocytosis cannot. by itself, " Req!.ns atlMnce01 dyW)ltliopoiesi$ and:~. discriminate between prenbrotc PMF and • Patients WIth an:libons associaled wilhreactve Ill)IlIofitlro llfe not mn.one kl PMf. ;rod . . ~ stxUd ET 12201, 2202. 22041. Constitutional be COIlSide1 lld n std1 cases ~ olhercntena are mel symptoms may include fatig ue. dyspnoea. I Degree of abnorrnalIIy could be borderline or martell . weigh l loss, night sweats. Iow-grade fever44 Myeloprolifera tive neoplasms
  • 44. and bleeding episodes, Gouty arthritis 1297.775.2202,22041 _In these cases the clusters of variable size that are frequentlyand renal stones due to hyperuricaemia BM biopsy is nvperceuotar with an in- edrecent tc 8M vascular sinuses and themay alsooccur. Splenomegaly of varying crease in the number of neutrophifs and bone trabeculae 1297.775,2204 .22161 .degee is detectedin up to 90% of patients atypical meqaaarvocv tes . There may be Most megakaryocytes are enlarged, butand may be massive: nearly 50% have a mild "left shin- in granulopoiesis, bu t small megakaryocytes may also be seen,tepa!l:megaty 1143, 366. 367, 1635, 2 1671. usually metamyeloc ytes. bands and seq- and theif detection is greatly facilitated byThe JAK2 V617F mutation may be found mented forms predominate. Myelob lasts the use of immunohistochemistry with an-n ~50% at patients in the fibrotic pha se: are not increased in percentage. and con- tibodies react ive with meg akaryocyticits incidence in the prefibrotic stage has spicuous clusters of blasts or of CD3 4+ antigens 1 2201, 22041 . Deviations fromno! been well studied. Althoug h helpful in progenito rs are not obse rved {2202 , the normal oucrear.cvtoptasmc ratio (andisllnguishing PMF from react ive condi- 22041_ In most cases, erythropoiesis is expression of defective maturation). an-boos thaI may result in 8M fibrosis, the red uc ed in qua ntity. but early erythroid normal pa tterns of chromatin clumping withmutation is not speci fic for PMF but is precur sors are promi nent in some pa- bulbous, "cloud -like" or "balloon-shaped"-tound in PV and ET as well 121721 . tients 122281_ The megakar yocytes are nuclei , and the frequent occurrence of markedly ab normal, and their ntstotoco- bare megakaryocytic nuclei are all typical graphy and morphology is the key to the findi ngs, Overall in PMF the megakaryo-The classical pic ture of advanced PMF recognit ion of the prefibrot ic stage of PMF, cvtes are more atypic al than in any otherincludes a PB smear that shows leuko- The megakaryocytes often form den se typ e of MPN. Vascular oronteeanon iserythroblastosis and anrsopoknocvtosrs(particularly with teardrop-shap ed redcells) associated with a hvp oceuura r BM Evolution _ Manifestation - - - - -•• Transformationwith marked reticul in andlor c ollagenfibrosis and organomegaly caused b yEMH, However, the morp holog ical and initiat Biageclinical findings vary c onsiderably atdiagnosis depending on whether thepatient is first encountered during theprefibrolic or the fibrotic stage of the disease (2177, 22041. Bec ause the pr o- - gr ssive accumulation of fibrous tissue e parallels diseaseprogre ssion, it is impo r- tant to reproducibly and sequentially grade the amount of BM fibrosis semi- ~ntitatively by using a sCOfing system 1 22141(T able 2.05). GJ PreffJroticandearly stage PMF :No registry- based prevalence ligures are available ~ b" the incidence otme prehbrotic pha se CD ol PMF, but series der ived from various e;,.",d MF-O MFo I Mf.2 Mf.] ~_I 11 I llfereoce centres reveal that 30-40% of Prefibrotic:-early PMF AdYilnced PMF (MMHJ patlerlIs arefirsl detected in a prodromal, preltbmllC phase without a significant in- Fig. 2.21 ~ oI lhe disease process 111 PfWnarY lIlJ8lDIiblosis (PMF) withassocialed ~ (lata crease in reticulin and/or collage n fibres (rrIllCWI values) arid associaIed fibre ~ Primary myekllibrosis 45
  • 45. usual in the 8M 11 214 1, and lymphoid Tlble 2.05 SemiQuanlitati~ grading of bone marrow fibrosis (MF). nod ules are found in about 20% to 30% GflIding 08$criptlon 1220 1, 22041 . Careful 8M morphological examination is particularly crucial in dis- MF • 0 Scatlemd ftar reticulin WlItl ro IOte~ (CIOS$-OWlIS), CO!reSpCJnding to normal booemarrow tinguishing pretiorotrc PMF with accom- MF- 1 loose networt of reliaJlin wltl many iltersections, especiallyin perivasa.dar ereas panying thromb ocytosis from ET 1712. 796,2 177.220 1.22161 Reticulin fibrosis . MF- 2 Diffuse arr:l dense increase In rebaJlin wrtll eJ:tenSlYe intersedtons. occasionally frilh local is minimal or even absent (corres pon din g burr:lles 01 coIagen and/or local OSleosderosis to grades 0 and 1)during this stage 122141; MF- 3 0l1fuse and dense II"lCleaSe IIIreticulin M!tl extensive IIIIer$edIons ilIICl coarse bundles of if present. It is usually foca l and tend s to collagen, often associated frilh ~ be concentrated around vessels . The rna- jority of cases with pretrbrotic and early (reticu lin) fibrot ic stages of PMF even tu- ally transform into overt ubronczscrerotrc myelofi brosis associated with EMH 1295. 775. 1189 , 2204. 22 181 . Fibrotic stage: Most pat ients with PMF are initially diagnos ed in the overt fib rotic stage 1143, 366. 1635, 2 1671. tn this stage the 8M b iopsy demonstrates clear-cut reticulin or collagen fibrosis (fibrosis grades 2 and 3) . The 8M may stilt befocally nvpercenurer, b ut more often is normocellular or hypocellular. with patchesof active naerretopoeers alterna ting withhypocel1ular regions of loose connectivetissue andlor fat. Foci of immature cellsmay be more prominent. although myelo-b lasts account for < 10% of the 8M cells{297, 775. 22041 Atypical megakaryocytes .are often the mo st conspicuous find ing ;these oc cur in large c lusters or sheets,often within dilated vasc ular sinuses 1295,2204). Sometimes lhe 8M is almost devoidof haematopoi etic c ells, showing ma inlyd ense reticulin or collagen fib rosis, withsmall islands of haematopo ietic precursorssituated mostly within the vascu lar sinuses.Associated with the de velopmen t ofmyelofibrosis is a sign ifica nt proliferation ofvessels showing marked tortuosity and lu-minal dis tension, often assoc iated withconspic uous intras inusoidal haemato-coese (1214, 1347, 1463). Osteoid seamsor eooossionarnew bone formatioo in bud-like endop hytic plaqu es may be ob served{775, 22041 In this osteoscl erotic phase. .the bone may form broad , irregular tra-beculae that can occupy >50% of the 8 Mspace. With exception of allogenei c stern ~~~) .. Fig. 2.23 Primary myelofibros fibrotic stage WlIIl ellrameduallary haemalopoiesis in Iivet A In the Mr, tie is, , .cell transplan tation 11592. 22131 develop-- , sirtUSOids are prominenUy involved by bilineage prolilerallOll. B Megakaryotyles are the hallrnart. 01 abnonnllment of myelofibrosis in PMF is not signifi- irltrasinusoidal haematopoiesis.can tly influence d by treatment modalities.an d is obviously related to disease p ro-gression 1 295. 22 17, 22181 · In patients with an a normal endosteal loc ation in the 8M acute phase . In cases with 20% Of morea previously established diagnosis of PMF, 12204. 22091. ind ica te an accelerated blasts in the PB and/Of 8 M at presentationthe finding of 10-19% bl asts in the P8 p hase of the disease, whereas ~% in which other find ing s may suggest PMF, Iand/or 8M and the oerectco by immuno- b lasts is consid ered as acute uanstome- the diagnosis 0 1 acute leukaemia shOOdhistochemistry of an increased number of I teo. Patients with PMF may also present be made with only mentiOnof the possibleCD34+ cells With cluste r formation and/or initially in an accelerated phase Of an derivation from PMF.46 Myeloproliferative neoplasms
  • 46. Extramedullary baenatoooleeta The most common site of EMH is the spleen , followed by the liver 117731. The spleen shows an expansion of the red pulp by erythroid, granulocytic an d megakaryocytic cells. Their identification can be aided by immunohistochemistry [ 16 13, 2 1991. which also allows an ap- preciation of an increase in neoanqioqen- esis / 144 . Megakaryocytes are often the most conspicuous component of the EMH. Occasionally large aggregates of rreqakeryocytes. growing COhesively can. ooocce macroscopically evident tt.mOUral lesions. In the presence of nodular lesions and , in general. in any advanced stage disease with large amounts of EMH, the PQS&bility 01 a myebd sarcoma should be c:onsidefed and carefully excluded by per- laming irrmunohistological studies with CD34 117731. The red pu lp cords may exhibit fibrosis as well as pooling 01 Fig.2.24 PrWncwy myeIoIilrosis. 6brollc stage . A ThIs penrtIerBl bloodsme<I" shows dac:ryotytes. occasionalnu::MaIed platelets. Hepatic sinuses also show pr0mi- red bloodeels <n:I irrrnalJ..nI grarUocytes ~l . BA dilaIed sinus corrtans inmaIIft tIaerrI.1qloiet nent EMH. and cirrhosis of the liver may elements, most notably megakaryocytes (p,f,$ stain) . ThiS intrasinusoidal haematopoiesi$ together oMth VilSClAr occur /21671. pn:iIeralJon is charadetisbcbutnot liagl105bC of PMF WIth myeloid rneIapIa:sia. C Megakaryocytes are olen the IOO5t conspicuous haemalopoielic element il the marrow Often !he cells appear to "s1ream"1Irough themarrow due 10 the In:lerI)tlg fitrosis. 0 Mcrled retJctjn and o:tagen Mln:lsII aSD:iated witha srreanHke arrargemenI of megakMyocytes Immunophenotype arld initial osteosclerosis is $hoIrm (slYerstaIn). No abnor mal phenotypic fea tures have been reported . Genetics No ge netic d efec t specific for PMF has been ide ntified 11832AJ. Ap proximately 50% of pat ients with PMF exhibit the JAK2 V617Fmutation. Althou gh the presence of the mutation confi rms the croneltty of the proliferation, it is a lso found in PV and ET and thus does not dis tingu ish PMF from these MPN {163 , 1044 , 1064, 1186, 1288J. A funct iona lly similar ga in-o f-f unc tio n mutation of MPL (MPL W5 15K/l ) has been repo rted in up to 5% at PMF cases. but in occasional cases of ET as wen /16891 Cytoge netic abno rmalities occur in . up to 30% of patients (630, 1832, 21 741. Postulated cell of orig in adversely affect pro gnosis include age There is no Philadelp hia chromosome or Haematopoi etic stem cell >70 years . Hb <10 g/d l , platelet count BCR·ABL 1 fusion gene. The presence of <1 00x l ()6/l , and an ab normal karyotype either del( 13)(q 12-22 ) or der(6) t( 1;6) Prog nos is and p red ict ive fac tors 11 42 , 143.366,630, 12 15 , 12 19, 1832A, (q21-23 ;p2 1.3 ) is strongly suggestive b ut The time of survival in patients with PMF 2105 ,2174,22041 . The major causes of not diagnoslic of PMF [5861. The most ra ng es from month s to d ecades. The morb idi ty and mortality are 8M fa ilure (in. common rec urring abnormalilies inc lude overall p rog nosis de pends on the stage tecnon . haemorrhage). thromboembolic del (2Oq), and partial trisomy 1q , allhough in wh ic h PMF is firstly di agnosed 11215. events , portal hypertension, cardiac failure +9 and/or +8 are also reported {63O. 22041. The median survival time is ap- and acute leukaemia (AMl) {21671. The 1832A, 21741. Deletions aNeeting the long proximately 3 to 7 years in patients diag- repo rted frequency of AMl ranges from 5 arms of ch romosomes 7 and 5 occur as nosed in the fibrotic stage {142 , 366 . 367 . to 30% 1366, 630 , 21671. Although some Nell. but may be associated with prior cy- 630, 2 167/. which contrasts with a 10- cases of AMl are related to prior cyto- totoxic therapy used to treat the myelo- and ts-vear relative survival rate of 72% toxic the rapy. many have been reported proliferative p rocess. and 59% respectively, in patients diag- in patients who have never been treated, nosed in the early prefibrotic phase confirming that AMl is pa rt of the natural 11215. 12191. Factors at presentation that history 01 PMF Primary myelofibrosis 47I
  • 47. Essential thrombocythaemia J . Thiele H M. Kvasnicka A.Orazi A. Tefleri H. GisslingerDefin ition EpidemiologyEssen tial thrombocythaern ia (Ell is a The true inc idenc e of ET is unk now n, bu tchronic myeloproliferative neoplasm (MPN) when di ag no sed according to the g uide-that involves primarily the megakaryocytic lines of the Polycythaemia Vera Stu dylineage. It is characterized by sustained Group (PVSG)115491. it is estimated 10 bethrombocytosis <!:45Ox l()1A.. in the periph- 06-2.5 per 100 000 persons per yeareral blood (PS), increased numbers of {1055. 10591. Most cases occur in patientslarge. mature megakaryocytes in the bone 50-60 yea rs 01 age , with no major sexmarrow (8 M), and c linica lly by ep isod es of predil ect ion. How ever, a second peak inthrombosis and/OI haemorrhage, Because frequ ency, pa rtic ularly in women , oc c ursthere is no known genetic or biological at about 30 years 01age 1705. 902 . 10551.marker specific lor ET. other causes for ET can also be seen in ch ild ren , albeit in-thrombocytosis must be excluded , in- frequently 118151, but must be distin-cluding other MPN, inflammatory and guished from rare cases 01 hereditaryinfectious disorders, haemorrh age and thrombocytosis 1585. 24011.other typ es of haematopoietic and non-haemat opo ielic neop lasms. The presence Sites of inv olvement Cli nical featuresof a BCR- ABL 1 fusion gene exc ludes the Bone marrow and blood are the principal More than one half of patients are asvrrp-diagnosis of El sites of involvement. The spleen does not tomauc when a markedly elevated platele! show signilicant extramedullary haemato- count is discovered lortUitously at the tJml!IC[).() code 9962/3 poesrs (EMH), but is a sequestration site of a routine PB count 1705, 802 , 902- for platelets 1705. 902. 21751. 2 1751. The remaining patients presetSynonyms with some manifestation of vascularPrimary thrombocytosis: id iopathic mrom - EtiOlogy occ lusion or haemorrhage 1210, 4581bocytose, haemorrhagic thrcrnbocythaemia. The etiolog y of ET is unknown. Microvasc ular occlusion may lead to trarl- stern iscnaemc attacks, digital ischaemia with paraestheeias. and gangrene 1210. 458 . 1473. 18291. Thrombosis of map arteries and veins also occur. and ET may be a cause 01 splenic or hepatic veil 1. SllSIairled platelet count ~45Ox 10"1t thrombosis as in the Budd-Chiari syn- 2. Bone marrow biopsy specimen showing proliferation mainly of the megakary ocytic line with increased age drome . Bleedi ng occurs mos t comrrow nlll11bers of9l1larged. matultl megakaryocytes. No signllical1t increase Of Iefl-sMtofOOlItrophiI glanoo- from mucosal surfaces. suc h as the gas- poiesis orer,1IWOpoiests trointestinal trac t or upper airway pas- 3. Not meetlng WHO atSerialor poIycyIIlaema vera,· PJINfY myelofIbrosI$.< BCR-ABL f posiWe ct.ror.: sages 1379. 802, 1549. 19551. If h myeIogenouIlMaetnia ormyeIodysplaslic syndrtml" Of oIher myeklid ~ criteria established by lhe PVSG 101 E1 4. Demonstration 01 JAK2V617F orolher donal maricer. or in !tie absenteofJAK2V617F, no e-.1dence lor are used. mild splenomegaly is present reeceve thrombocy1osls approximately 50% of pa tients at diagnosrs and hepa tome ga ly in 15-20% 1705, 802. • Sustatned ooring the W(ri.-up process. 902, 1549 , 2 175 1 How ever, when !he • Requires Itle fcMure of iron repIaoement ItIefapy toincrease IIaemoglcOf1 level10I!oe polyc)1IIaemia "llfa WHO classification is applied and pa- fange Illhe presence of deaeased serum lerTilin. Ex<iJsion ofpo/ytyltIiIllfllia vera is based on haemoglobin tients with thrombocytosis associated rod hilemiIIocrtIeve!s and red eel mass meiISl.Ifement is not required. the p relibrotic stage 01 primary myeIcj. • Req.wes!he absence 01 relevartre!iQjn Ibosis. coIagen fitl«l&s, ~ ~~ , Of markedly hyperceIuIar marrow aetOll"C3ried by megakaryocyte IIUphoIogyIhat III lypicaI for primary brosis (PMF) are excluded. spIencrneg<I, myelofibrosis ifIcludtng smaH 10large rnegakaryocytes WIth an aberranl nuclearl~smic ratio iIfId is seen in only a minority of patients hyperchromatic. bulbous Of irregularlyWed noc~ and dense dusterirlg. ET112151. Rare pa tien ts who meet the • Requires the absence of BCR·ABL 1. terra for ET have been repo rted to half • Requires abserloe ofdyserythlopoies and llysgranulopoiesis. noncronat meqakervoc vtoootests eoe I , Causes of reactive thrombocytosis iIdude I/Ofldeficiency. splenedomy. StJfgefY. nedion. inllammation. tower incidence of thrombo tic epi alM8CtIVe!lssue disease . melastIticcancer. and ~trve disorders However. the presence of a cendIOOn iIS800ated wllll reactiveborrtlocyt)sis may noI edJde fie possility d ET t!he fnl wee 19011. kry relationship of such cases 10 criteria are met vast majority of cases 01 ET that clonal haematopoiesis is not clear.48 Myelopro liferative neop lasms
  • 48. In ee past, the platelet threshold for the a normocel lular or moderately hypercel- present. the increase in granulopoiesis isdiagnosis of Er was :!:600x109/l115 49J, lular 8 M {775, 22161 The most striking ab- . usually only of mild degree. There is no in-but some patients have haemorrhag ic or normality is a marked proliferation of crease in rnvetobtasts nor is myelodys-ltuombolic episodes at lower platelet megakaryocytes with a predominance of plasia observed, The network of reticulincents 11272, 1829, 19031. In order not to large to giant forms displaying abundant, fibres is normal or only minimally in-C01lprcmise the diagnosis in such cases, mature cytoplasm. and deeply lobulated creased in ET. and the find ing of signif i-a number of investigators convincingly and hyperlobu lated (stag- horn like) nu- cant retic ulin fibrosis or any collagenargued tOl" a lower platelet thresho ld for clei. The rnegakaryocytes are usually dis- fib rosis excludes the diagnosis of ETee diagnosis of ET. and the WHO has persed throughout the BM but may occur 1712, 775, 796, 2177, 2205, 22161. Boneadopted the recommenda tion of a platelet in loose clusters. Bizarre, high ly atypical marrow aspirate smea rs also reveal theCOltlt ~450 x 1 l)lIL, a value that exceeds megakaryocytes, such as those observed markedly increased numbers of mega-!he 95th percentile for normal platelet in PMF, are not found in ET and if present. karyocytes of large size with hyper lobu-counts adjusted for gen der and rac e the diagnos is of ET should be ques tioned tared nuclei and . in the background. large (1 272. 1897, 1903.21771. Although this 1712, 796 , 2200 , 22051. Proliferation of sheets of platelets. Emper ipoles is of BMllYeshoid will encompass more pat ients erythroid precursors may be found in a elements is frequentl y observed in ET. but 1Io!lh ET, it will also include more pat ients few cases, p articularly if the pat ient has is not a spec ific find ing. Stainable iron is I4lCCflditions that mimic ET. It is therefore exper ienced haemorrhages. but granulo- present in the aspira ted BM specimens of essential that all Criteria listed in Table c ytic proliferation is highly unusual; If 40-70% of patients at diagnosis 116491 . 200 for the diagnos is of ET be met to ex- ewe olher recotastc and non-neoplast ic causes 01 thrombocytosis 1 1771. The 8M 2 bi:psy is particularly helpful in exc luding ere myeloid neoplasms associated with excessive platelet counts. such as myelo- dysplastic syndrome (MDS) associated wltrl isolated del (5q). the prov isional lr)eIodysplasticlmyeloprohferative entity refractory anaemia with ring sioerobras ts and thrombocytosis (AAAS-T), and the cetoronc phase of PMF. Althou gh the JAK2 V617F mutation is fou nd in only f ig. 2.27 Essential ttwombocylhaerm bone marrow asplate smear. AAll increase in the nurrtler and size of the a, 40-50% ot cases of ET and is not specific megailaryocyles. B NoIe the deeply Iobutaledmegakayocytic ~, as well astarge pools01 pla te~_ Note that the aspirate smears fail to reveal the overall marrow archilecture anddistribution of the rnegar.aryocytes thatcan be (Illy b ET, when present it does exclu de re- seen in the biopsy, ectve mrorroocv tosrs 121771. Similarly, in eeo enocqeroue erythroid and/or meg a- karyocytic colony formation, althoug h not specrlic tor ET also exc ludes reactive , ltYombocytosis 159 41.MophologyThe major abnormality seen in the PB ismarked thrombocytosis, The plate letsoften display anisocytosis, rang ing fromtiny torms to atyp ica l large, g iantplatelets. Bizarre shapes, pseudopodsand agranular platelets may be seen, butare rot common. The white bloo d ce ll(WEq count and Ieueocyte differential~e usually normal, although a borderlineeevaton in the WBC count may occur(705,802.902, 21751. Basophilia is usu-aMy absent or minimal 115491 _ The redblOOd cells are usually normocytic andrcerccnrcnc unless recurrent haerror-mage has caused iron deficiency, inW"Mch case they may be hypochromicand microcytic. Leckoervtnrobleetosts¥d teardrop-shaped red blood cells areIQ seen Il ET 121751. ~ rrosl cases, the BM core biopsy shows Essential thrombocythaemia 49
  • 49. react ive thrombocytosis , An abnormal karyotype is found in onl y 5-10% of pa- tients with ET when d iagnosed according to lhe previou s PVSG criteria {15491. There ; is no consistent abnormality. but those reported include +8, abnormalities of 9q, and del(2Oq) {939, 1682 1 Ahhoogh isoIatoo . del(Sq) has also bee n reported in ET. cere- lui rrorphologic examination is required 10 distinguish such cases from MOS associ- ated with this abnormality 116821. Postulated ce ll of ori gin Haematopoetc stem cell. Prognosis and predictive factors ET is an indolent disorder characterized by long symptom-free intervals, inter,The lTIOfphological findings in the 8M may initially present wittl thrombOCytosis ruptec by occasional ute-mreatenbiopsy are essential to distinguish ET from without leukocytosis and can mimic ET cl~ thromboembolic or haemorrhagic epis-other MPN. myeloidosooes and reactive ;cany. AJ1hough !he ""90 rnegaJ<ao,ocytes of odes 1705, 802, 902, 12 15, 154 9, 2175conditions tha t p resen t with sustained ET can be easily distinguished from the Although after many years a few patttlrcmbOCytosis , The finding of even a mild sma ll -dwarf" megakaryocytes of CML. cy- with ET may develop 8M fibrosis associ--degree of combined granulocytic and ery- togenetic and! or rroecuer genetic analy- ated w ith mye loid metaplasia (EMHmroo proli feration should raise considera- sis to exclude a BCR-ABL 1 fusion gene is such progression is uncCllTYTlOl1 1297, 775.tion of prodromal stage poIycythaemia vera recommended for all patients in whom a di- 1189.22201. Precise diagnostic guide-(PV) 122101. and the finding of granulocytic ag nosis of ET is considered 11841 1. lines lor diagnosing post-Ef MF are givenproliferation associated with biza rre. hig hly in Table 2 .07 . Strict adherence toatypical megakaryocytes should p rom pt Immunophenoty pe and other WHO c riteria 1143A . 21771concern lor the prefibrotic slage of PMF No aberrant pherotype has boon described necessary to prevent diagnostic comus12201,22231 . Significant dyserythropoiesis associated with early PMF accompaor dysgranulopoiesis sug gest a d iagno sis Genetics by thrombocytosis 1365}. Transformation~of MOS rather than ET. The large me ga- No mol ecular genetic or cytogenetic ab- ET to ac ute myeloi d leu ka emia or MOOkaryocytes with hy per lobulated nucle i of ET normality specific for ET is known. Approx- occurs in <5% of patients, and whencontrast with the medium-sized monoio- im ately 40-50% of cases ca rry the JAK2 does occur is likely related to previousba ted megakaryocytes associated with de l V617F or a functi ona lly sim ilar mu tation cytotoxic therapy 1705 , 802, 90 2, 1800(Sq ) as an isolated ch romosom al abnor- 1163. 1044,1064.1186.1 2881, Thesemu- M ed ian survivals of 10-1 5 yea rs aremality in MDS and with the small. dysplas- tatoos are not specific for ET and are found common ly rep orted . Beca use ET usu al~tic megakaryocytes associated with the in PI and PMF as well, A gain -of-Iuncti on occurs late in midd le age. the [,Iainv(3)(q21q26 2) or t(3;3)(q 21;q26.2) chro - mutation of MPL. MPL W515K/L , has been ex pecta ncy is near normal for m an~mosomal abnormality. Lastly, some patients reported in 1% of cases of ET {16891. None patients {1215. 1702 , 2200 . 2430}. Fi nal~with c hronic mye logenous leukaemia (CML) of these mutations are found in cases of it is noteworthy that the maj ori ty of c lini stud ies are based on prev iou s d iag l10stic gu id eline s 11 549 } that fail to d ifferentiateTable 2.07 WHO diagnosbc cnleria lor posl~ssenlial thrombocythaemia myelofibrosis (post·ET MF), clearly between the early prefibrot R.quired criteria stages of PMF wit h accompan ying thr 1. Documenlatioll of a prevklus diagnosis of WHQ-defined essential ttlrombocythaemia bocvtosrs an d ET ac cordi ng 1 the 0 2. Bonfl marrow fibrosis grade 2-3 (011 0-3 scale) or grade 3-4 (oo 0-4 scale ) classification 11215, 2200, 2205} . A su stannat d ifferenc e in ove rall prognosis Additional crittril (2 are ~j..-cl) been reported w hen these two di ffer 1. Anaemia« 22{1dl decrease from baseline haemoglol*1leve1 ctessmcanon sys tems are ap plied to 2. A leukoefythrobla pe~ bloodpiclufe same pa tien t population 112151. 3. Incr&aSingsplenomegaly defiMd as &$ler an Increase in palpable splenomegaly of>5 emfrom baseIne (lislance Ircm ltIeleft C05laI margin) orIle appearance 01 newly p.alpable splenomegaly 4. Increased LDH (atloYe reference level) 5, Development 01 >1 of3 CXlIlSlrtlllional s~ : >10% weight bss in 6 month$. right sweats, I,Il8lplBined illver{>37.5-C150 MyeloproliferatIVe neoplasms
  • 50. Chronic eosinophilic leukaemia, BJ. Bain D.G. Gi llilandnot otherwise specified J W , Vardiman H .-P. Horny-Ctwooic eosinophilic leukaemia (CEL) is amyeloproliferative neoplasm (MPN) inwhich anautonomous. clonal proliferation01 eosinophil precursors results In per- can be fou nd , and w hich is associated with sig ns of organ involveme nt and dys- function 1443, 23821; there is no evidence for eosinophil clonality. It is a diagnosis 01 exclusio n. and may inc lude some cases pa rt. The epidemiological features of cases of HES that rema in idio pathic have not vet been c learly d efined. Sites of involvementSistently increased numbers of eosiro- of true eosinophilic leukaemia that cannot eEl is a multisystem disorder. The PBptliIs in the peripheral blood (PS), bone currently be reccqnrzeo. as we ll as cases and BM are alwa ys involved . TIssue infil-matrON (BM) and penooerarnssoes. with 01 cytokin e-d riven eo sino philia that are tration by the eos.roonns. and release ofeoSKlOPh~ia being the dominant baema- due to the ab normal release of eosinophil cytokines and humoral factors from thek*lgical abnormality. Organ damage cc- gr owth fa ctors, e.q . interleukin (IL) 2. 3 eosinophil g ranules lead to tissue dam-ClSS asa result oueceaemc infilt ration or and 5, fOf unknown reason s (128 , 443 , age in a number of organs, but the heart.ee releaseof cytokines, enzymes Of other 1971. 2072 , 238 21. lungs , central nervous system, skin andproteins by the eosinoctas. Chronic gastrointestinal tract are commonly in-eosinophilic leukaemia . not otherwise ico-oeeee 9964/3 voiveo. Evidenc e of sp lenic and hepaticspecified, (GEl. NOS) excludes patients invo lvement is p rese nt in 30-50% ofWIth a Philadelphia (Ph) chromosome, Synonym patients 1443. t97 1. 2072 , 23821 .BCR-ABL llusion gene or rearrangement Hypereosinophilic synd rome (not recom-01 PDGFRA, PDGFRB or FGFR1. mend ed) . Clinical featuresIn eEL, NOS the eosinophil count is Sometimes eosinophilia is detectedn5xl ~1L in the blood. There are fewe r Ep idemiology inc identally in patients who are otherwisethan20% blasts in the PB or 8M . To make Due 1 the p revious dilfic ulty in d istin- 0 asymptoma tic . In othe r pa tients, co nstitu-adiagnosis 01CEl. there should be evi- gu ishing CEL f rom idiopat hic HES. the tiona l symp toms , such as fever, fatigue ,dence/or clonality of the eosiropbus or an true inc id enc e of these di seases is cough, ang ioed ema . musc le pa ins, pr uri-ecreese in myeloblasts in the PB or 8 M. unknown, althou g h th ey are rare . Many tus and d iarr hoea are found . The mo stIn many cases however, it is impossible to patients wh o wou ld until rec ently have serious clinical findings relate to endomyo-proyeclonalrty 01 the eosoo ptuls. in w hich bee n c lassified as hav ing idiopathic HES c ardi al fibrosis . with ensu ing restrictivecase, if there is no inc rease in blast ca n now be show n to have C El assoc i- ca rdiomeg aly. Scarring 01the mitralltricu -cells, the diagnosis of "id iopathic hyper- ated w ith a FJPtL 1-PDGFRA fusion gene spid valves leads to valvula r regurgitationeosinophilic syndrome" is made . The {466 1 Since this co ndition oc cur s mainl y . and formation of intrac ard iac thro mbi,idiopathic hypereosinophilic synd rome in ad ult me n, the male dominanc e and the w hich may embouze to the brain or else-(idiopathic HES) is de fined as eosi no- peak inc ide nce in the four th decad e w here, Perip heral ne urop athy, cen tra lphilia (~1.5~ 1CfJ/L) persisting for at least 6 prev iously descr ibed in "HES" {443 , 1971 , nervou s syste m dy sfu nction, pulmonarymonths, for which no und erlying ca use 2072, 2382 ) are now exp lained , at least in symptoms due to lung infiltration, and Chronic eosinophilic leukaemia. not otherwise specdied 51
  • 51. rheoma toroptcar findings are other fre-qu ent ma nifestations (443, 1971 , 2072 ,-2382 1In CEL, NOS the most striking feature inthe PB is eosinophilia, there being mainlyma ture eosinophils with only small num-bers of eosi no p hi lic myelocytes orpromyelocytes {443. 710, 12OJ. 1971, 2072,23821. There may be a range of eosinophilabnormalities, including sparse granulationwith clear areas of cytoplasm, cytoplasmicvacuolation, nuclear hype rseg men tationor hyposeg me ntati on, and enlarg ed size,These c hanges ma y be seen in cases ofreec uve as well as of neoplastic eosino-philia, however, and are thus not veryhe lpful in deciding whether a case is likelyto be CEl {1281. Neutrophilia often ac- , , .com pani es the eosinophili a , an d some Fig. 2.31 Ch ron ic~oop/l i l ic ~uk.aem ia . Peripheral blood smear from a patient With ahistory ofpersjstent eosi1c?* ec ases have monocytosis, M ild basoph ilia Immatureaswell as mature eosinophilsarepresent CyloQenebc arlalysis showed trisomy of chromosome 10, tiChas been reported 17101, Blast cells maybe present but are less than 20%.The BM is nvoercenotar due in part to disease 1128. 19311. In addition, a num- are immunophenotypical1y aberranl an:! 1 meosinophilic proliferation 1289, 443. 710, ber of neoplastic disorders such as t-een tha t mayor may not be clonal 1286, 1156. Nc1200, 2382 1 In most cases, eosinophilmaturation is orderly, w ithout a d isp ro por- lym phoma, Hodgkin lymphoma, sys tem ic ma stocytosi s, acute lym p hob last ic leuk· 202 41. When such an aberran t T-c ell pop. ulati on is presen t, the case is not CEl00 m,tio na te inc rease in m ye loblasts. Ch arcot- aemia and other MPN may be associated is it idiopathic HES. If the monocyte con G.l eyden crystals are often present. with abnormal release of Il2, 1 l3, ILS or is > 1x1r:P1L a diagnosis of chronic mye;o. NoEryttTopoiesiS and megakaryOCytopoiesis GM-CSF and a secondary eosinophilia monocytic leukaemia with eosinoptlUare usually normal. The finding of in-c reased num bers of m yelob lasts (5-19%) tha t mimics CEll 128 , 1168, 1172, 1450, 1616. 1924, 1931,246 11: in systemic mas - may be more appropriate, but if there are dysplastic features and> 10% neutrophl "" ;d a, •supports a di agn osis of CEl, as does the tocytosis there can also b e eosinop hils precu rsor s in the PB and no rnonccytoss. Faob servation of dysp lastic features in other be looging to the neo pl astic clone. The BM a d iag nosis of atypical chronic myebdcell linea g es. M ar row fibrosis IS seen in should be carefully inspected for any leukaemia with eosinophilia should Sifn. lusome cases 1289, 7101. Any tissue may process which might explain the eosino- larly be considered. cashow eosinophilic infiltration and Charcot- philia as a secondary reaction, such as The distinction between GEl. NOS. arc witleyden crystals are often present. Fibro- vasculitis, lymphoma, acute lymphoblas- idiopattuc HES is important. Idiopattlc GElsis is a common find ing . an d is caused by tic leukaemia , sys tem ic m as toc ytosis o r HES can be diag nosed onl y in fUlly inves- conthe d egr anu lati on of the eo sin op hile wit h gran ulomatou s d isorders. Some cases of tigated pa tients and on ly when (i) there, maOthe release of eosinophil basic protein persistent eosinophilia are due to the ab- an eosinophil count of <!:1.5x 1()l11l perse asand eosinophil cationic proteins {443, normal release of cvtocnes by t-eens that ing lor at least 6 months; (iil reaclM 1931 ,2382} .Differential diagnosisD iag nosis re qu ires posi tiv e evidence of 1. There iseosinophilia(eosinophil count <!:1,5x1(ll1L)the leukaemic nat ure of the co ncnton and 2. Thefe is no Ph chrorrosome or BCR-ABL 1 fusion gene or oItIer myeloproliferative neoplasms (PV ET. PMF) .exclusion of cases of MPN with re- orMD5ItolPN (CMULIX ICML)arrangement 01 PDGFRA. POGFRB or 3. There is nott.5;12)(q31-35.p13)« ohIr ream1l9B"*~of PDGFRBFGFR1. The diagnostic process often -4 There is no FlP1l1-PDGFRA fusion gene crotherrearrangement 01 PDGFRAstarts wi th exclusion of reactive eosino-phil ia. A d eta iled histor y, physical exam i- 5, There is noI88rrangemerlt of FGFR1na tion, b loo d count an d blood film ar e 5. Theblast cell count in the peripheral blood and bone marrow is less than 20"10 and there is 110essential. Conditions to be excluded l(15)(p13Q22) IX 1(16;16)(p13;q22) IX oIher lealureGagrlosbc ofAMLinclude parasitic otectoo. allergies, pul- 7. There is a cbIaI cytol}eneIiC or rnolecaar genetic abnormaIrty, IX bIasleels aremore lhan ~ in !he ~ bk:Jod« men than 5% in !he bone marn:owmonary d iseases such as Loetners syn-drome. cyclical eosinophilia. skin diseases ·If apatient haseoiil"lOPhilia bul lhese mlenaare not met !he dial;Joos4S may be reactive eosinopt1ilia,idiOpa1tMcsuch as anqictymphoid hy perplasia, col- hypereosinophilia or idiopathic hypereosinophilicsyndrome,la gen vascular d isorders and Kimu ra s52 Myeloproliferative neoplasms
  • 52. eosinophilia is excl ude d by appropriate • h:lrcxJgh investigatoo ; (iii) AML. MPN, MOS. MPN/MDS and systemic ma stocytosis are excluded; (iv) a cytokine-prod ucmq. ~icalty-aberrant. t-een pop - ulation is excluded; (v) and there is tissue damage as a result of hyper eosinophilia . Hcnteria i-iv are met but there is no tissue damage. the app rop riate d iagnosis is ocoamc hyperoosinop hilia . Patl8rlts in whom a diagnosis of idiopathic Itypefeosinophilia or id iopalhic HES is made should be kepi und e r reg ular review since evidence may su bsequently Emelg8 that the con dition is leukaemic in !laue, Treatment may also be necessary e,tlchemstry Cytochemical stains c an be used to identify eosinophils bu t they a re no t essential for diagnosis , Partial degranula- eco can lead to eosinop hils ha ving _.- F"l9- 2.32 kiopaltiC HES. Ablood smeard a pabertWlth ca-dIaclai.n,1eukotyt:lsi$ and~ . - reduced peroxidase con tent. whether the eosinop hils are pa rt of the Prognosis and predictive factors No specific immuno p henotypic ab ner- clonal process. since react ive eosi nophilia Survival is quite varia ble. In some series malily has been reported In CEL. can occur in patients with myeloid neo-- in which pat ient s with idiopathic HES as pla sms 17111. However, the linding of a well as those with probable eosinophilic Geretics recurring ka ryotypic abnormality that is leukaemia were incl uded. 5-year survival No single or spec ific cytogenetic or usually ob served in my elo id d isord er s. rates ap proached 80% 1443. 19 71,2072, molecular genetic ab normality has been suc h as +8 or i( 17q), does suppo rt the d i- 23821. Marked splen ome g aly. as well as identified in CEl. NOS . Cases with re- agnosis of CEl 1128, 1692 ). Occasiona l the find ing of b lasts in the b lood or arrangement of PDGFRA, PDGFRB or pat ients have a JAK2 mutat ion 1106 41 . inc reased b lasts in the 8M , cvtcqeneuc FGFRI are spec ific ally excluded , The x-unkeo polymorphism ana lysis of the abn ormalities and dysplastic features in detectOO d a Ph cbrcroscre or BCR-ABL 1 PGK or HUMARA genes c an oc ca sionally othe r my eloid lineages have been re- fusion gene ind icates one of the rare be used in fema le patients to dem onstrate ported to be unfavourable prognostic cases of chronic myelogenous leukaemia cionautv 1392, 13501. find ings [443, 1971. 2072 ,2382]. wnh dominant eos inoph ilia . rather than eEL. Ellen when eosinophilia occurs in Postul ated cell of or ig in conjunction with a ch romosomal abnor- The ce ll of orig in is a haemopoietic stem m ality that is usually mye loid neoplasm- cel l, b ut the lineag e potential of the associated, it may be difficult to decide affec ted cell may be var iab le. Chronic eosocobtc leukaemia. not otherwise specified 53.
  • 53. Mastocytosis H ,-P Horn y n.o. Metc alfe C. Akfl L Escribaro J.M . Bennett P. Valert B,J . Bain Definition Solitary mastoc ytoma Mastocytosis is due to a c lonal, neoplastic of skin 9740/1 prolife ration of mast cells thai accumulate Indolent systemic in one or more organ systems. It is char- mastocytosis 974 1/ 1 acterized by the presence of mult ilocal Systemic mastocytosis compact clustersor cohesive aggregates! withAHNMO" 97 41/3 infiltrates of abnormal mast cells. The d is- Aggressive systemic order is heterogeneous. ranging from skin mastocytosis 97 41/3 lesions that may spontaneously regress to Mast cell leukaemia 97 4213 highly aggre ssive neoplasms associated Mast cell sarcoma 974013 w ith muttiorgan failure and short survival Extracutaneous Fig. 113 Cutaoeoos maslOCytosiS. Darier"s 91- TIl (Table 2.09). Subtypes of mastocytOSis are mastocytoma 974011 skit lesions 01 III bms 01 0Jtane0us IIa:Stlc)t::s recog nized mainly by the distribution of ~ wIlen stroked A. palpable wileaI ~. IN the disease and cli nical manifestations . In "AHNMO, ass oc iated naematoioqrce! moments afterhlltJysical sllrIUatIon, lkJe" hi,.. cutaneous mastocyt osis (eM), the mast c lonal non-mast cell d isorder 0I1t1slamnt from !he mastcells, cell infiltration remains confined to the skin, whereas systemic mastocytosis Synonym (SM) is characterized by involvement of at Mast cell d isease . least one extracutaneous organ with or without evidence 01 skin lesions . Masto- Epidemiology cytosis shoul d be strictly separated from Mastoc ytosis may occur at any age Cu- mast cel l hyperplasia or mast cell activation taneous mastocytosis is most common in slates without morphological an dJor m0- c hil dren and may be present at birth. tecuer ab normalit ies that characterize the About 50% of afflic ted chil dren develop neoplastic proliferatio n. typical skin lesions before 6 months of age . In adults. CM is less frequently diagnosed IC[)..() codes than in ch ildre n 12055 . 2436 1. A slight Cutaneo us mastocytosis male predominance has been rep orted in (urtica ria pigmentosa) 9740/1 C M. SM is generally di ag nosed after the Diffuse c utaneous second decade of life ; the ma le to female mastocytosis 9740/ 1 ratio has been report ed to va ry from 1:1 to 1:31 181, 1465, 1694). Table 2.09 Classification of mastocytosis. Sites of involvement Fig. 2.34 Cutaneous mastocytosis, Numeroos typi:;i , Cutaneous mastocytosis (CM) Approximately 80% of patients with mas to- eac nar and maCtllop.apular pigmented eseu ct 2, Indol&nt s)5t&mic mastocytoSis (ISM) c ytosis have evid ence of skin involvement urticaria ~gmentosa in a young child " {16871 . In SM the bone marrow (BM) is al- 3. Sy5temic mastocytosis wittl associatedclonal most alwa ys involved, so morp hological haematological non-mast-celliineage disease and molecula r anal ysis of a BM b iop sy (SM·A.HNMDj specimen is stron gly rec ommend ed 10 4 AggressiwSy5temic masklc)toSis (ASM) con firm or exclude the diagnosis [287. 5, Mast cellleul<.eemia (MCl) 290, 971, 12751. Rare ly. the pe riphe ral 6. Mast c:eII sarcomlI (MCS) blood (PB) shows leukaemia due 10 sig- 7. Ertacutaneous meslocytoma nificant numbe rs of circulating mast ce lls {972. 14841. Other organs that may be in- volved in SM inclu de the sp leen. lymph For the partlClpl!lms 01 the Vear 2lXXl Wortung Group nodes, liver and gastro intest inal tract mu- ceeeeece on MesOCytOllS .....no ~ flo.ooIved in the def,r1llJOIl 01 cr<terlll and WHO cIassohcllllOll 01rresto- cosa, b ut any t issue may be affected C)lOSIS C Alr,1l . KF Auslen . Jt,4 Bernett. AD BrI.roning. 1287,966.968.973, 1275, 1334. 1466. Fig. 2.35 Ditluse artaneous mastocytosrs. TIOenC. l Elicr lbano. H-P Horny. I( lerIlerI. CVI.J JB Longley, . 1694 1. Skin le sions occur in more than reddlShpeau ~ 1esic:In$ dIaacteIisbc oIlilta G Marone. 00 MelC8Ne. A Nunez . MA P_aresch. LB Sct>warU. I( Sollar. ~ $perl. P V8Ienl. .IN laid.. 50% of SM pat ients, and are more often cutaneous mastocytosis This variant ocan am:.. man. K WOlIf observed in those with an indol ent course. exdusiYely in d*eIl 54 MyeloproliferatIVe neoplasms.
  • 54. In contrast. aggress ive va riants of SMoften present without skin lesion s [97 11 .However, some SM patients withou t skinescos may on occasion present wit h anindolent form of SM, most often isolated8M mastocytosis. ICIricaI featuresCutaneous mastocyt osis includes severalcetrct cmco- nistocettoicqcar en tities.l esions of all form s 01 CM may urticate Fig. 2.36 Indolent syslelTllt mastocytosis. Densewhen stroked ("Dariers sign 4 ) and most infiltrate conSisting mainly 01 spind~ stitJ1Iysnow intraepidermal accumulation of ~nUar mast eels.melanin pigment. The term wtcana 4ptgmentosa mac roscop ically describessese two clinical features. Blister ing("b.bJs mastocytosis") does n:lI representa separate subtype but rather an exaq-geralion 01 urticaria. Blistering is usuallyseen IrIpatients less than 3 years of age.m may be assoc iated with all forms ofceeoanc CM 11 68 7, 2055, 24361.Symptoms in SM at presentation havebeefl grouped into 4 c ategor ies: 1) con-SbtUtIOO8! symptoms (fat igue, weight loss,Mr, diaphoresis). 2) skin manifestations Fig. 2.38 Indolent systellic mastoeylOSis. A loo5eIy scattered spmdHhaped tlypograrlular mast cells WJlhooI(prurituS, urticaria, dermatographism). tendency III awegate. Diagnosis is lacihlatedIfhen addibonal imrrI.rnostaHWI and moIeaJIar analysis n performed. B IrrITlIAlOSlain withCD25 shows an atypical ~ 01 mast eels with rnentlralle assooated reactivity. 31mediator-related systemic events (ab- dcminal pain. gastrointestinal d istress ,Dushing. syncope, headache. nvpoienson. tachycardia. respira tory symptoms) and 4) musculoskeletal complaints (bone pain. oeteoceora steoporoers. frac tu res, o <JltIralgias, myalgias) {181, 22901 . These symptoms range from m ild in many pabents to severe, life-threatening med iator- related events in othe rs, Sym ptoms ma y also be related to orga n impa irme nt (du e 10 mast cell infiltrates), pa rticularly In patients with high-grade ag g ress ive or eukaernic disease variants, Physical findings in SM at d iagn osis m ay InClude splenomegal y (o ften minimal). lltile~dooopalhy and hepatome galy are foond at signif ica ntly lower trequen- cies !966,968, 973. 1275, 1466 1. Organo- rnegaly is often absent in the m ost rormon variant. indolent systemic masto- cytOSis(ISM). but is usuall y p resen t, alo ng w impaired organ function, in aqq res- Fig. 2.39 Systemic mastocytosis, Skeletal lesions ate common in systemic masloc,1OSiS. This X-ray shows paldty SNesystemic mastocytosis (AS M) an d in osteosclerosis, osteoporosls WId multiple IyIiclesions mille lemur , leukaemic variants. Severe systemic ~s may occ ur in patients w ith ISM infiltration of the g astrointestinal trac t by failure is encountered only in patients with bbwIg eceosve release and generatIOn excessive numbers of abnormal m ast aggressive or leukaem ic disease varian ts. rJ bcctemcar mediators including tusta- cells P8 1. 1334 , 2288 1. Significant numbers of circulating m ast I!fe. eicosanoids. poteases and heparin. Ha ema tologica l abnormalities in 8 M celts are rarely observed and are sug- For example, gastrointestinal symptoms include an aemia , leukocytosis, blood gestive of mast cell leu kaemia 122901. In S.d1 aspeptic ulcer disease Of diarrhoea eosinophilia (a frequent f inding). neu- up to 3)% of cases with SM. an associated , n more corrmonly attributed to release tropenia . and thrombocytopenia 1130, clonal haematological. roo-mast cellileage rJ biologiCally active mediators than to 287.7 13.971 , 1162 , 16871. Bone ma rrow d isease (AHNMD) is d iag nos ed before. MasfOCytosis 55
  • 55. T~ble 2.10.Criteria lor cutaneous end system maslocytosis ic infiltration patt ern is def ined as loosely Cutaneous mastocytosis (CM)" scatte red mast cells in the absence of SIOO lesions demonslrebng!he typical dinicallindlng5 ofUPIMPCM. diffuse cutaneous mastocytosis or soIttary compact aggregates. It must be noted. mastocytoma, and lypiCBltlistoIogical i1filtrates 01 masl cells in a lTlJltJlocal or dlfIuse ceeem in anadequate skill however, that this pattern is also observed biopsy. Inaddition. a tiagnosbc prerequiSIte b thediagnosis of CM is theabsence 01 features/aliena in reac tive mast cell hyperplasia and in sufficiant toestablish the ~s 01 SM cases of mveromastccvnc leukaemia. a °l/p(laled and &I9llly modified cnteliab skin i1YO/YemerJt in mastoey!OSiS have recetlUy been suggested {<t7A}. term used for cases with advanced myeloid neoplasms in whom elevated S)Itemic mastocytosis (SMI numbers of immature atyp ical mast cess The diagnosis 01 SM CBl be made when the IIIaJOI critenon and one IIIirIa criterion or at least Ihnle mnor are found , but criteria for SM are not met crrteIia are prMelll 120651. In patients with the diffuse infiltra- tion pattern it is therefore impossible to lIIajor crilerion; establish the diagnosis of mastocytosis t.UlrfocaI, dense rliIlrates rJ mast eels (::!:15 mast celI$ n ~) deleded i1 sections of bone IIllIITOW Without ad ditional studies including the and/or OCher eltraaAaneous organ(s) demonstration of an abe rrant illYTlUfl(} phenotype and/or detection of an acliva!· Minor criIW: iog point mutation in KIT1977, 978 , 1196 1. In biopsy sedJons rJ bone nwrow orOlIlItel1raCUlaneOuS organs, :>25%ollhe mast eels r11he 2056,20571 , In contrast, the presenced infihle are ~ orhaveatypocaIlll(llllI1CJIog or, d aI mas! eels n bone m.arrtMasprate rruttifocal compact mast cell infiltrates ora smeaR, :>25% aremnalln oratypical. diffuse-compact mast cell infiltration pattern ......... 2. Deleclion of an ICtiYaIIlg poI"It rnutalI:Wl at c:odor1816 of KIT~ bone manow. blocdor anolher eJ:lraCula. 3. MastOBIs itI bone marrow. blocdor oItler eJhcutaneous organs express CO2 andorC025 in adl;1itlOII ~ is highly compatible with the diagnosis d mastocytosis during first inspection. H0w- ever, additional immunohistochemical aId nonnat mast 011 maR-eB. molecular studies are strongly reccn- <t 5enJm tolaI tryptase pet1istetllly exceeds 20llgIml(unless!here is an associated daIaI myeloid dIsordar it , wtictI caselhisparamet9f 1$ not valid). mended even in these cases. In tissue sections stained with H&E, ~ reactive mast cells usually are loosely sca ttered througho ut the sample, andsimultaneously with. or after the diagno- is an assoc iated clonal myeloid non-mast display round to oval nuclei with clumpedsis of SM. In princi ple, any defined cell disorder, in which case this parameter ch romatin, a low nuclear/cytoplasmicmyeloid or lymp hatic malig nancy may is not valid. Serum trypta se levels are nor- ratio. and nucleoli that are absent CIoccur as the AHNMD. but myeloid neo- mal to slightly elevated in mos t pat ients indistinct. The mast cell cytopl asm isplasms predominate, and chronic myelo- with CM and have also been found to be abundant and usually filled with smallmonocy tic leukaemia (CMML) is most independent of the patients tryptase faintly visible granules. Dense aggregatescommon 197 1, 9 75. 2056, 2066, 2095, hap lotype 11977, 2290). of mast ce lls are only very exceptionalfy22901. In patient s with SM-AHNMO, clini- detected in reactive states or in paterecal sympt oms and disease course relate Morphology treated with stem cell factor (SCF) 11 275both to the associated baematoioqrcat dis- The diagnosis of mastocyt osis requ ires 1694. 22901. In smear preparations, mastorder and to SM 11977, 2290). demonstration of rnultifocal clust ers or ce lls are read ily visible in RomanowskySerum tryptase levels are used in the co hesive aggregates/infiltrates of mast stains as med ium-sized round or ovalevaluation and monitoring of patients with cells in an adequate 8M biopsy specimen cells with plentiful cytoplasm , con ta in i~mastocytos is, The finding of a pers istently (Table 2, 10), The histolog ical pattern of densely packed metachromatic granuleselevated serum total trypta se > 20 ng/mL the mast cell infiltrate may vary according and round or oval nuclei. In norrnarreaois suggestive of SM and is used as a to the tissue sampled 1130, 290 , 7 13, 966, tive states, mast cells are easily dislilo"minor" criterion for diagnosis, unless there 968 ,973, 1162, 1466 1. A d iffuse interstitial guished from the smaller metactvonacFig. 2.40 Typical skin lesion of a dIld WIlh ur1icatiapigm&nIosa. Aggregales of mast cells Iil Ihe papIIafydemIII ald edllnd as 5he8ls into Ile f8tJCWr clemis.56 Myeloprol!ferative neoplasms
  • 56. TIIbIt 2.11 SubdaSSlf?tiOn 01cutaneous mastocy1osis, Table 2.12 Criteria lor variants 01 systemic mastocytosis I 1. ~ pioJnenIosa (UP V~ 1. IndolentsystemicmlStoeytosis(ISM) ewneous mastoeylosis (MPCM) Meets arteria b" SM. No"C" findings (see below). No evldence of afl associated non.roastc:ellileage cJonaj 2 DIuse l:lJWoeou$ mastocylO$ls I1aematOOgicaI mali1laflc.yldlsonlel" (AHNMOI· In !hisvanant. !he mast cellMOefllS low and skin 3, Sl*arI mamcytomaof skin lesions areaWnosI ilVaria ~ present 1. BDnemarrow mastocytosisbasophils which have segmented nuclei, As above (ISMI wiIIl bone marrow involvement. but noskin lesions .and larger and fewer granules. With en- 1.2 Smouldering systemicmastocytosiszyme cytochemistry. mast cells reac t As above (ISM), but wItl 2 oc ITIOle "8 fn:l1llgS but no "C" ffldings. strongly wrth naphthol·ASD-chlofoacetateesterase (CAE) but do not express 2. Sptemie mastocytosis with n soeiBted clonal hMmaI~ norHnUt c:.Illl. . . . disease (SM-rnye!operoxidase In mastocytosis. the AHNMO)cylOIogy of mast cells vanes, but aboor- Meets CriIeria torSU and cntenalor an assoaaled. donIlIlIIemaloklgicI flOIloITIaII eel lineage disorder .!tal cyIo1ogic features are almost always AHNMO !MOS, MPN .AJ.IL,~ . oc ott. ~ neopasm tIal meets !he aliena b" aoetected. nckJdlllQ marked spindling and disbnd~ " tie WHO cIasslticaIm ).hypOgrarJJlarrty 122901.Cytanorpnoiogical atypia is pronounced 3. AggrlSSivt systemic: mastocylosis (ASM)11 higtl-gfade lesions 01 mastocytosis.* ee occurrence of metachromatic ...... Meets c:nena b SM. <n oc IOOf8 "C" Indings. No ll"olci8rOI of maslceI-..aema. UsuaIy ri1oU: smees cells being a usual feature 01 mast 3.1 l~hic mastocylOiIs with t<l5ioophililcelleukaemia 122901. The finding of tre- Progessive ~ wCh penphefaI bloodeoswlOphIa orten Wllh extensrve borle .QUeft mast cells with bi- Of multi lobated irlvoIoemeol. and tep<l~ . butusuaIy IIIIlnJI skin lesions. CasesWIltIINI~~ m~. ...... "Idei rpromastocytes") usually indicates of PDGFRA weelCkJded.if! aggressive mast cell proliferation.aIItOJgh these cells may be seen at low .t. Mast c:elileukaerrlia (MCl)IreQuency in other subtypes of the dis- Meets cnteria lor SM Bone marrow biopsy shows a ~ lrlfiIIrabOn. usualy oompacl. by aIypicaI, . immaturemast cells. Bone IT1arnllr aspirate smears snow 2O"It or more mast eels In typitaI Mel . mast ease 122901. Mitotic figures in mast cells cells aa::ountfor 10%oc more of~ blood wtIIte eels. Rarevanllfll: aleukaenK mast c:el leukaernla Ii) occur, but are infrequent even in the - as above. but <1 0% ofwlile bloodcells aremast cells. Usualy wiIhouI sbl lesions aggressive or leukaemic variants of SM. Kl assess mastcell numbers with cowen- 5 Mas. c:ell 5MComa (MeS) lO"aISlalning procedures, Giemsa or toiu- . lJfIifocaI mast celllurrOJr. No evidence 01 SM. OeslluClive growtl pattern. HiQh1lrade cytology, - idine blue are employed 1 detec t the 0 6. Extlillcutaneous mastocytoma metachromatic mast cell g ranules and UnilocaJ mast ce ltlTlOU, Noevidence 01 SM. Noskin lesions. NoOOestruetiYe !1owth pa ll ttern, Low-grade CAE IS alsohelpful 122901 However, the . roost specitc methods lor ide ntific atio n of nmature or atypical mast ce lls in tissue -8" findings sectons utilize immunohi stoch emic al 1. Bone marrow biopsy showing >30% infinratkin bymast cells (focal, ceose aggregates) andlor serumlolal s taimng fortryptase/chymase and CD 117 lryptase level >20 nglmL. and, for neoplastic mast ce lls. C0 2 and 2. Signs of dysplasia or myeloproliferation. in ten-mast ceil lineage(s). but insufficient criteria for definitive CD25, The morpholog ic features of th e diagnosis of a haematopoietic neoplasm(AHNMD), with nonnal or only slightly abnormal bloodcooors common subtypes of mas toc ytos is are 3. Hepatomega ly withoutimpairment 01 ~v&r function , andlO!" palpatlle splenomegaly without hypersplenism, tescnoeobelow. and/or lymphadenopathyon palpalfon or imaging "C" findings 1_ Bone marrow- dyslunction mal1lfasted by ooe Of mor cyOI)a!1ia (ANe <1.Ox101l.. Hb <10 gJdl, lX e Cutaneous mastocytosis (eM) platelets <1 Clli10"Jt). but noobvious noo-m ceU haematopoielic malignancy as! 2, Palpahla !lepatDmagalywiltl impa irment oI ~ver 1uncIlon. ascit s and/or portal hyperterlSior1. e ~dk19nosis of eM requires the d emon- 3. Skeletal i1oOioeman1 withlarge osteolytic lesions d Ol palhologtcallractures. strahon of typical clinical find ing s an d .t. Palpablesplenomegaly W hypetSJlielVsrn. ith VSlOIogical proof of abno rma l mast ce ll atoo ol the dermis (Table 2.10). In S. Malabsorption WlIh we9Jl loss due 10 GI mast cell infiftrates, cases a isolated eM there is no evide nce . ~ systemiC involvement using such oa- Urticaria pigmentosa (UP)lmaculopapufar the retic ular dermis, et ten in per ivasc ular 1Il"ell!fS as elevated levels of total ser um cutaneous mastocytosis (MPCM) and pena dnexar pos itions 1 24361 A sub- . ryptaSe or organomegaly. Recently, con- This is the most lre q uent form of CM. In variant. usually occurring in young children. snus craeria for the diagnosis of CM child ren,1he lesions of UP tend to be larger presents as non-pigmented. pl aqu e-form- Il8ve been further relined. and three and papular. Histopathology typically re- ing lesions. In adul ts . the lesions are d is- • vanants of CM are now recogniZed veals agg regates of spindle-shaped mast seminated, and tend 10 be red ex brown-red 1atIIe 2111122861. cells filling th e papilla ry dermis and ex- and macular or maculopapul ar. Histo- tending as sheets and ag gregates into pathology of adult UP tends to reveal Mas tocytosiS 57
  • 57. Rg. 2.43 A Booe marrow smear of a patJenI WIth indolent systemiC masUytosi$ The eel is atypical. witIlan indenled nucleus in an eccentric Iocabon, and cytoplasm ... .... .an ~ emson WIt1 ~ dIslr1buIim of ~ 8 Sysl8rlIc rnastlc)tlsIs. The eels may haw bland ru:lel WIIIl moderate ~ of 1* tyqllasm , spinIed _ _ .." .....IMeITtlle fibroblasts. or IctllAated nuclei WIth ab.nln dear C)kIpIasrn The Ialler eels mayresermle rnonoc:ytes or his/ioqIes. and ant more oommooly seenin aggnssiftfewer mast cells than observed in chil-dren. The numb er of lesoner mast cells Diffuse cuta neous mastocytosis This clin ically remarkable subvanent of upper reticu lar dermis. In massively treted skin , the histological picture !Tllf •may sometimes ove rlap with the up perrange of mast cell number s found in nor- CM is much less frequent than UP and presents almost exclusively in childhood . be the same as that seen in solitary mas» cytorna 12055, 24361. •mal or inflamed skin. In some cases, Here the skin is diffusely thickened and cexamination of multiple biopsi es andimmunohistochemical analysis may be may have a peau chag rine or peau da- ange (orange peel) appearance. There are Mastocyt oma of skin This oc cu rs as a single lesion, almost • cnecessary to establi sh the diagnosis of no individual lesions. In patients with cl in- exc lusively in infants. without predi lecl~ neM 12286, 2436). ica lly less obvious infiltration 01 the skin, of site. The histolog ic picture is one ~ s the biopsy usually shows a band-like sheets of mature-appearing highly meta- infiltrate 01mast celts in the papillary and chromatic mast cells with abundant C/I> plasm that densely infiltrate the oa and reticular dermis . These mast eel trates may extend into the suocoteoece Cl tissues (11541 . Cytological atypia is na a detected . This allc:Ms separation 01 mas» cytoma from an extremely rare mast eel sarcoma 01 the skin 119581. w Systemicmastocytosis (SM) sa He The prerequisites for the diagnosis of So! di, are outlined in Table 2.10. In most cases. ex ag greg ates 01 atypical mast cells a1 era readily found in tissue sections. The crtt9ll lor variants 01SM are given in Table 2.12. fr Bone marrow In most cases of SM, multifocal . sllar~ demarcated compact infiltrates 01 rna; of cells are the most common and easily ce s tect able feature in the BM bio psy. The my infiltrates are found pred ominantly If pl. paratrabecutar and/o r perivascular loca- my tions 1 290, 965, 971, 977, 978. 11981 The . 00< focal lesions are co mprised 01 varyiOj d islFig. 2.45 SystemiC mastocytosis, booe marrow bklpsy. A The local lesions01 mast cellschenconsist of a central core numbers of mast ce lls. intermingled w 0ol lymp/lOCyles, surrourldlld by polygonal mast cells with pa~ . faintly lJ"iJrlUlarcyIOplasm. WIth reactive eosinophils at varying numbers of lymphocytes , eoere qUEthe outer margirl ol lhe lesion. 8 The lesiOns are often well-circumscribed. and may OCCIJ" irl parauabecular or phils , tusnocytes. and fibrob lasts. These 148perivascular Iocabons, but may be IlVldorTWy dislnbuted in the interllabeclAar regionsas wei. diagnostic "mixed" infiltr ates are o/tell he58 Myeloprol!terative neoplasms
  • 58. seen in ISM and generally show eithe r a should be classified according to estab- disorders, including myeloid and especially central core of lymphoc ytes surrounded lished WHD criteria . II is important to note lymphoid neoplasms, such as lym pho- bymastcells, or a central compact mast whether the re is inc reased cellularity of plasmacytic lymphoma or hairy c ell eel aggregate with a broad rim of lym- the marrow or d isturbed maturation of leukaemia 122901 In such reactive states , . phocytes 1 9651· In other cases , the le- haematopoietic cell s, because. even if the predom inantly round mast cells lac k sions are mot e rronorooptec and are c riteria lor a coexisting myeloid neoplasm major" cytological atypia. and are almost many composed of spindle-shaped are not completely fulfilled , hypercetlutarity always loosely sc attered throughout the mas! cells that abut Of stream along the Of abnormal myeloid maturation patterns tiss ues. a find ing that c learly contra sts bony trabeculae 1977 . 9781 . Significant cou ld be associated w ith an unfavourable with the compact aggregates 01 reooiastc relJCulin fibrosis and thickening of the out come (progression to ASM or SM- spindle-shaped mast cellsfound in masto- ad lacent bone are frequently Observed . AHNMD) or with a smouldenng variant of cyt os is 1 22901 . ScrnetIITles. the 8 M space is d iffuse ly re- SM in which the out come is uncertain The d ocumentation of 8M involvemen t placed by compac t mast cell infiltrates , 122901 Inter pretation of findi ngs must in- . accompanying SM is usually established which may resemble sheets of fibroblasts clude consideration that reac tive , non- by examination 01 a 8M trephine biopsy 1 9711. Marked reticulin or even collagen clonal mast cell hyperplasia may specimen. However. the analysis of mar- fibrosi s is frequentl y observed in such accompany a var iety of haematolog ical row aspirate smears does provi de useful cases 1971 , 977, 9781. Usu ally, there is a mixture of both spind le-shaped and round mast cells. Rarely, co mpac t infiltrates may exclusively consist of round hype rgr anu- af mas! cells, which meets the criteria for so-called trvptase-c ostnve round cell llfiltratioo 01 8 M (TRDCI-8 M) 1 9761 In . cmrest to spind le-shaped tryptase- expresSing cells that are alw ays mast cells, the round nvptase-posmve cells in TROCI are either mast ce lls (coexpres- 9IOll li C0111 and c hymase), neoplastic !laSl:ViIS (primary or secondary baso- Fig. 2.46 Systenic masb;ylosls, spleen, A Sl)Ieen tom a paletIt lIIi01 systenic maslIXylosls. B Aggregates rJmast It1k leoIo:aemial or myeloblasts in the eels may be seen II tie red orwliIe pulp, orbolh. ~ his case, mast eels ate seen II a penloIi::IJNlocation. sett.ng of a trvotase-oosmve acute lIyflIOId eokaene. CaretlJ inspec tion of the 8M no t at!ected by mastoc ytosis is of crucial ecctarce. Often, the una ffected 8M is II1remarkable with a normal distribution of tal cells and haematopoenc p rec ursors . Such cases usually eithe r belong to ISM olthinvOvemen! of skin and 8M , or re pre- SMt isolated mastoc ytosis of the 8M , However, in othe r c ases th e 8M not drectly infiltrated by mast cel ls may be extremely hypercellular due to the prolif- escoof cells of non-mast cell lineages, tduding neutrophils, rnonocytes. or less frequently, eosoopbns or b last cells. De- PQ"Ong on the type of proliferating cells, eese lindlngs may be reactive (myeloidI ~ ), or may indica te the presencet d acoexisting naematoooeuc neoplasm ll.d! as acute myeloid leukaemia , ae ~ollferatiYe neoplasm, a myelodys-• syndrome or myelodysplasliC/ ~ferati ve neoplasm, Of chronice ...""llc ~. Lymphoproliferahve9 diseases, such as plasma cell myeloma ~ malignant lymphoma. are less Ire- (JJllflIyseen 1110, 969 , 971, 975.1 147 , Fig. 2.43 SM-AHNUD (acutemyeloid Iel.Jkaemia). A The streaming, spindled eels of a largemast eel aggregate can~ 1484 2056,2066, 20951. In all such cases, be seen on one side rJ lhe booy lrabecUkJm (arrow), weeeas a rTlCIllOIonoUs J)Opljabon of blast cellsis seen onlhlIm ~ associated naematoroorc d isea se opposite side . B The spiodledcells of mastcell disease abut on a large aggregale of blasts. Mas tocy tosis 59
  • 59. granulomatoid lesions in the caranecec- ular and paratoucurar areas. or within the lymphatic follicles, or as diffuse infiltrates within the red pulp. As in other tissue sites, eosinophilia and fibrosis are fre- quently observed in areas of mast eel infiltration. In some cases. an associated haematolog ical disorder may be present, but this is often difficu lt to diagnoseusirgA splenic tissues alone 1973, 14661. Liver Liver involvement in SM usually presen With disseminated small granuloma t foci of mast cells within the periportal tracts and as loosely scattered mast eels within the sousoos . Severe liver i~ rrent is only rarely seen in SM. WiderWg and fibrosis 0 1 periportal areas is cct- monly found . but fully developed cirrhosis... C is rare 1966, 14661 .f~ 2,49 SystemicmastlcyloliswiltI associ8led hl*yt:ell Waerria. A Bone marrow aspiaB smear Wllh hairycelsand al)1liCal mast eels B The spirded mast cells M pteSel11 adjacentto the hairy eel ilfiItJate il lhe intersbbaI Gastrointestinal (GI) tract mucosaregions oI1he ITilIOW Although hairycelleubemia may occasioRaIy assume a spindledlTW)IJlIlology, in Ihis case lhe Involvement 0 1 the GI tract mucosa bfmast eel tryplase lustrated in (e ) dearly demonslrales !he mas eel origin 01 ltle spindled tens. alll! an l mastocytosis is frequently suspected ctn-imuIostaIn for C020 idenlifles ltle IIaify eels in (D). ically but may only rarely be assessed morpholog ically. As in omer tissues, •additional information and is c rueial lor the have been reported 1 belong to a defined 0 least one compact mast cell infiltrate isre-diagnosis of mast ce ll leukaemia and 01 subset of ASM, namely "Iymphadeno- quireo to support the diagnosis of SM. IfIsome suovanante of $ M-A HNMD 122901. pathc SM with eosinophilia" 11484, 22901. typical cases. these mast cells shOw anIn ISM, most mast ce lls are found within In such cases, studies for rearrangement of abnormal immunophenotype with expres-the thicker regions of the aspirated PDGFRA are recorrmeoded, and if present, sion of CD25, and an activating poirtcrushed fragments. Mast cells in ISM, the cas e should be reassigned to the cat- mutation of KIT is present. Due to the Ire-which should always be assessed in the egory of myeloid neopla sm with eosino- quency of CD25- positive lymphocytes.thin region s and at a fair di stance from philia and rearrangement of PDGFRA. careful examination of the tissue is rec-8 M part ic les , usually com p rise < 1% of all essary to avoid false positive results. T onucleated marrow ce lls. This is in contrast Spleen eva luate a GI biopsy for mastocytosis,to mast ce ll leukaemia, where mast cell The white and red pulp of the spleen may both antt-trvotase and anti-C0117 antinumbe rs b y defini tion equal or excee d be involved in SM, with rare case s show- bod ies should be applied in order to20% of all nucleated cells in aspirate ing preferential infiltration of the lymphoid avoid false positive results due to strongsmears 1290, 977, 978, 2290}, follicles of the wh ite pulp (9731 . Here. bac kg round staining when only ant~ mast ce ll infiltrates often present as focal tryp tase ant ibodies are used. A lewLymph nodeLymph nodes appear to be rarely in-volved in 8M in that significant lym-phadenopathy is unusual. The mast cellinfiltrates within lymph node s may involveany of the anatomical compartments butparticularly involve the paraooncat areas.Mast cell infiltrates can be either foca l ordiffuse, but rarely totally efface preexistingarchi tecture. Hyperplasia of germina lce ntres, evide nce of angi oneogenesis,tissue eosinophilia, plasmacytosis and reti-culin/coll agen fibrosis usually accompanythe mast cell infiltrates 1968. 14661. In afew patients, lymphadenopathy is marked ,with a progressive clinical co urse mim-ick ing malignant lymphoma . II Sig nificantblood eosinophilia is present. such cases60 Myeloproliferative neoplasms
  • 60. exceptlOll3l cases exhibit a diffuse com- Of osteoporosis is another frequent find- application 01 appropriate immunohisto-pact infiltration of the lamina p ropf"ia mu - ing in patients with mastocytosis, and chemical markers, particularly anti-tryptasecosae by atypical mast cells , and this may occur in any variant. and anti -CD l17 . AlthOugh initially local-fB1 reseroe inlIanTnatory bowel disease ized , distant spread followed by a terminalr:1 malignanl lymphomaat first glance . AI- phase resembling MCl is seen alter aklgelher, lour patterns of involveme nt of Mast eel/leukaemia (MCL) short interva l. Mast cell sarcomas havetheGI tractmucosa by mastocytosis can been report ed to occur in the larynx, largebe dlscnminaled 1171 1 1) Loosely scat- : In mast cell leukaemia , mast cells equal bowel, meninges , bone and skin 1265,tered mast cellswithout dense ag gregates or exceed 20% of all nuc leated cells in 970, 11761 .W wrth an atypical immunophenotype aspi rate smears 1 290 , 977, 9 78, 22901. Inand an activating point mutation of KIT, this rare and hig hly ag gressive lorm of usual~ in the settinq 01 SM of some dura- SM , the BM reveals a diffu se, compac t Extracutaneous mastocytoma ioo and involving the 8M, 2) Slight in- infiltrate with marked redu ction of fat ce lls crease in loosely-scattered mast c ells and normal haematopoietic precu rsor s. This localized tumour consists of an withoccasional dense aggreg ates and an The mast ce lls often show sign s of ac cumulation of mature-appearing gran- atypical rrmoopterotvce with expression marked atypia with hypogranu lar c yto- ulated strongly metachromati c mast cells , ct CD25. usually associated with an actr- p lasm, irregularly shape d monoc ytoid or in contrast to the hig hly atyp ica l mast ~ating point mutation of KIT, 3) Diffuse b ilobated nuclei (p romas tocy tes), and cell s observe d in a mast c ell sarcom a. Cl:lmpaCI infill ralion 01 the mucosa by may even pr esent as me tach romatic Extra cutaneous mastocytoma is excep- atypiCal mast cells, resembling the ag- b lasts 122901. In some cases, the nucleoli tion ally ra re, and the reported cases ~ive variant of SM in other tissu es may be prominent. In typ ical cases , mast involved the lung {3981. 171 1and 4) Localized mast cell sarcoma cells ac c oun t for 10% or mo re of the (based on one published case with in- c irculating nucleated cells . If mast cells Irrm.mopheooIype OteTlerC oIlhe ascending colon) 111761. comp rise less than 10% the circulating Mast cells co-express COO, CD33, CD45 ,_ 1esK>ns cens. the diagnosis of an "aeukaem.c" variant of MCL is appropriate 122891. CD68 and CD 117 but lack severa l rnyelomonOCytic ant9S"S, including CD14,The lfequency of bone changes varies CD15 and CD16, as well as most T- and ee subtype of disease. -hile pu re B-eell related antigens 1974, 977 , 978 , tduse ceteoscerosis is unusual in ISM Mast eell sarcoma (MCS) 1073, 1292, 1687, 22901 Virtually an mast , Iil(:U 6%0), it is observed in about one cells , irrespective of stage of maturation dWl:lol patients with ASM. The most com- Ma st cell sarcom a is extremely rare and or neoptasnc state , react with antibodies llOIradlOlOglcallinding associated with cha racterized by a localized and de- against trvp tase . a cell not expressing ISM crests of concurrent osteosclerotic struc tive growth of highly atyp ical mast tryp tase ca nnot be id entified as a mast andOSleolytic lesions (45%). Osteopenia cells, which c an be id entif ied only after cell immunohistoc hemically. Chymase is Mastocvtose 61
  • 61. expressed in a subpopulation 01 mastcells. Chymase is highly specific butmuch less sensitive for the identificationof atypical and immature mast cells than .. •." . ~ ~ . e ~C0117, whereas COl17 expression is ahighly sensitive but rather nonspecificmarker of mast cells. Neoplastic mastcells show a similar antigen profile to thatof normal mas t cells, but in con trast tonormal mast cells. they also coexpressC02 or C02 and C025, These latte robservanons are of considerable value inthe diagnosis and in the differential diag-nosis of mastocytosis and related tumours,and can be applied in immunohistochem-ical as well as in flow cytometry studiesj650, 1655. 205n The application of anti-C025 enuoooree has been found particu-larly useful in the histopathologicalevaluation lor suspected SM. Howeve r.C02~posilive T-cells are usually present intissues and must be taken into account Fig. 2.53 Mast celleull.aem&a A ~ blood smear. Note lhe biIobed ru:tel and relatively ~before an atypical C02-positive mast cell cytoplasmoften seen in Itll5 awessive form of rnastIcykIIas. B Theborle marrow biopsy is li1IuseIy inIiIlr.*ldbypopulation can be properly iden tified . p.J. ~slJC mastcells, C derronslriIles !he dear aIr appearance !hat is due ~ !he poorgratlJIalion of the """" .......together, it can be assumed in the routine ltIatis typical of inmature mast eels ofmast eelleukaernia. 0 All irmI.JnohisD::h slainbr masteel ~diagnostic evaluation 01 mastocytosis thatcells expressing uvptaserctrsmase andC0117 are mast cells, and cells coax- The DB16V mutation is identified in the SM associated with myeropronteratsepressing tryp tase/chymase, COl17 and mast cells of 95% or more of adults with neoplasms. JAK2 V617F may be foundC02/C025 are neoplastic mast cells SM when sensitive methods are used, in- The de tection of the FIPIL 1-PDGFRA120571. C025 expression may be incon- clu din g nested PNA-PCR or PCR on fusion gene has been reported in patientsstant or even unde tectable on mast cells poo led micro-dissected single mast cells, with mast cell proliferation and eosinophiliain some rare subvartants of the disease, Other activating point mutations of axon 122861. Although patients presenting wltIsuch as welt-dilt erentiated SM or in a sub- 17. such as DB16Y, D816H and 08 16F elevated serum trvptase levels. clonal8Mgroup 01patients with mast cell leukaemia are rarely seen {756. 1332, 1333, 20561 . eosinophilia with a F/P1L1·PDGFRA1141. The DB16V mutation is seen in only about fusion ge ne and a few scattered atypical one third 01CM in paediatric patients 114, mast ce lls have been described as havingGenetics 1331, 1332) and the frequ ency of point an unusual variant 01SM {130, 713, 11621Mastocytosis is frequently associated with mutations other than 08 16V is significantly most of these patients do not fulfili 8Msomatic activating point mutations within higher in CM than in SM, In patients with criteria, particularly as compact mast celK IT 121761. In most cases, co don 816 SM-AHNMO, add itional ge netic defects infiltrates are missing , and they are bestmutations in the tyrosine kinase domain may be detected, depending on the type classified as a mye loid neoplasm W ithare detectab le. Rare familial cases with of AHNMO. For example, in SM associated eosinoph ilia and rearrangement 01qecmune mutations of KIT have bee n with AML, the RUNX1-RUNX1T fusion PDGFRA (See Chapter 3) 122871.repo rted [ 14,15, 1331,1332, 1333, 1557, gene may be found , whereas in cases of21761. In patients with SM-AHNMO addi-tional genetic de fects are det ec ted,depending on the type of AHNMO,Somatic point mutations of the KIT protQ-oncogene that encodes the tyrosinekinase recept or for SCF are de tected asrecurring abnormalities in mastocytosis11 4,15, 1331, 1332, 1333, 1557, 1656,21761 _ The most commonly observedmutation shows substitution 01 Val for Aspat codon B16 (D816V). This mutationresults in ligand-independent activation 01KIT tyrosine kinase and provides relativeresistance to the prototypical tyrosinekinase inhibitor imatinib 1995, 15571.62 Myeloproliferative neoplasms
  • 62. Postulated C~ II of oriQin elevated alkaline phosphatase and hepato- disease often have no skin lesions 122901Haematopoietic stem cells. splenomegaly. The perce ntage and mor- However. isolated 8M mastocytosis as a phology of mast cells in 8M smears have sobvanant of ISM with excellent prognosisPrognosis and predictive factors been ide ntified as additional important also presents without cutaneous lesions.In children, CM usually has a favourable and independent pred ictors of survival in If there is an associated baematoroqrcetoutcome and may regress spontaneously mastocytosis 122901- malignancy, the clinic al course and prog-before or during puberty. In adul ts, cu ta- Currently, there is no cure lor SM. and the nosis are usually domina ted by this re-neous lesions generally do not regress prognosisdepends on eediseasecategory lated haematological malignancy 1 9751_and are. in contrast to a previous belief, 1228 7, 22881. Patients with high-grade Patients with aggressive SM generallyoI1en associated with SM, usually the (agg ressive) disease inclUding mast cell show a rapid cl inical course with a sur-ocoient variant. One study identified leukaemia may survive only a few months, vival of only a few years. MCS shows apredictors of a poorer prognosis as rate whereas those with indolent SM usually prog ressive course with death withinonset of symptoms , absence of CM. have a normal life expectancy 12287. months . Patients with ASM, Me l andttrembocytopenia. elevated lactate dehy- 22881. SM patien ts with cutaneous MCS are thus candidates lor cvto-ciogenase (lOH). anaemia. 8 M hypercel- invotvement usually also follow an indolent reduc tive therap ies.k81ty. qualitative PB smear aboorrehtes. course, whereas patients With aggr essive MastocytosiS 63
  • 63. - Myeloproliferative neoplasm, H.M. Kvasnicka B.J . Bain unclassifiable J , Thiele A. Orazi H.·P. Horny JW , vardiman Definition wren clinical data necessary for proper a number 01 other naenatopoeuc and The designation. myeloproliferative ne0- c lassification are insufficient or not avail- rco-neenatcooenc neoplasms, suchas plasm. unctassmaore (MPN . U) should be able, when the bone marrow (BM) speci- lymphoma or metastatic ca rcinoma , may applied only 10 cases that have definite men is of inade q uate q uality or size for infiltra te the marrow and cause reactive cl inical, labora tory and mor pholo gical acc urate evaluation (1216, 22 16 , 22221 or , changes, inc lud ing dense fibrosis and fea tures of an MPN but that fai l 1 meel 0 w hen there has bee n rece nt cy totoxic or osteosclerosis that ca n be misconstrued the criteria for any of the specific MPN growth factor therapy - p rob lems that ac- as an MPN 122061. Dete ct ion of a clonal entities, or that present with featu res that count for the ma jority of the unclassifiable cytogenetic abnormality, a JAK2V617F a overlap two or more of the MPN ca te- cases encountered in routine practice . In othe r functionally similar JAK2 mutatIOn, gories. Most cases 01 MPN. U, will tall into such cases it is often preferable to de- or an MPL IMP/.. W515K1L) rrutation one of three groups: 1) Early stages of scribe the morphological findings, and to distinguish an MPN from such reaclrve poIycythaemia vera (PV), primary myelofi- sug gest additional cl inical and laboratory conditions, although not all cases of MPN brosis (PMF) or essootial thrcmbocythaemia p rocedures tha t are nee ded to further U express a currently recognized aeretc (El) in which the c harac teris tic featur es classify the p rocess, inClud ing ad eq uate marke r 12171, 21771. In add ition, thedefin- are not vet fully d eveloped: 2) Advanced pe riphe ral blood (PB) and BM biopsy and ing c harac teristics of each MPN must be stage MPN, in wh ic h p ronounc ed myelo- aspi rate specimens. When a d iag nosis of considered with the realization that, as with fib rosis. osteosclerosis. or transformation MPN, U is made, the repo rt should sum- any other biological process, variations 00 to a more aggressive stage (r.e . increased marize the reason for the difficulty in occur, and they may progress thrt:llJ!1l blasts and/or dysplasia) obscures the reaching a more specific diagnosis, and. different stages so that the c linical 31"(1 underlying disorder 1775, 1216, 2206, if possible, specify which of the MPN can morphological manifestations of the dis- 22 16,22221 : or, 3) Patients with convincing be excluded from consideration . ease will change with time 12177, 2216 1 evi de nce of an MPN in whom a coexisting If a c ase does not have the features of neoplastic o r inflammator y d isord er ob- one of the we ll-d efined entities, the pos- ICD..Q code 997 513 scures some of th e diagnostic c linic a l sibility that it is not an MPN must be and/or morp hological featur es , The pres- strongly consi de red, A reac tive 8 M re- Epidem iolog y ence of a Philadelphia (Ph) ch romosome, sponse to infection and inflammation, lox- The exact incidence of MPN, U is ur*~ BCR-ABL 1fusion gene or rearrang eme nt ins, chemotherapy, and administration 0 1 but some reports indicate that the pel- of POGFRA, POGFRB or FGFR 1 genes growth tactors. cvtokmes and irrmuno- centage of unclassifiable cases ecccn excludes the diagnosis of MPN ,U. suppressive agents may closely mimic for as many as 1~ 15% of all cases Ii The diagnosis MPN,U shou ld not be used MPN and must be exc luded, Furthermore, MPN 1775, 2222 1 The frequency varies , 64 Myeloproliferative neoplasms
  • 64. significantly aCGord ing to the exper ienc e l1lhe diagnostician and the specific eras- sfication system and criteria utilized to dassifyMPN 11216, 22161. ElOOgy The cause is unknown. Sites 01 W1voIvement 5mlar to the other MPN cncaJ leatures r-e dI1icaI features 01 MPN. U are similar Iltoseseen in the other MPN, In pat ients , . early, tn:: lasgjfjable disease, organo- -regaly may be minima l or absent. but sclen:lmegaIy and hepatomegaly may be T8SSNe i1 those with advanced d isease " "IIton 8M scecerees are characterized (post-Pv MF) or rarely ET (post-ET MF) a myelod ysplaslictmyeloproliferative reo- 0, ~ myek)flbrosis and/or increased 1143A1 and lhe overt fibrotic-osteosclefotic plasm, incl uding the provisional entity, re- rurtlers of blasts 122161. The baemato- stage of PrlAF may be impossible if there is fractory anaemia with ring sidercblasts ~ valles are also variable , and range no previous history or histology for review and thrombocytosis, should be considered rem mild leukocytosis and moderate to 12203 22CXi, 2216, 22221· Although Chrc:K1ic , 11 27,1 29,865.1 245,1406.2082,2169/. I.arlo:ed thrombocytosis, with or without myelogenoos leukaem ia (CMl) may also ~nying anaemia, to severe cvto- be accompanied by marked myelofibro- Inwrunophenotype PfJ8S ae 10 8M failure. Some patients wilt1 sis, the sma ll size of the megakaryocyt es No abnormal phenotype has been re- 1IlN. Upresent WIth otherwise unexplained will alert the morphologist to the correct di- ported for this group of patien ts. p:fIai or splanchnic vein thrombosis. agnosis, and cytogenetic and mole cular qenetc demonstration of the Ph chromo- Genetics Iil<pI<JI<lgy some or the BCR-ABL 1 fus ion gene will There is no cvtcqenetc or molecular krrtcases that are diagnosed as MPN. U con firm the di agnosis of CMll775, 2216. genetic finding specific for this group. tJemQ to very early stage disease in 22221. There is no Philadelphia chromosome, iItlCJ the differentiation between ET, the More than 10% b lasts in the PB or 8M BCR·ABL 1fusion gene , or rearrangement p"e librOlic stage of PMF, and the pre- and/or the findin g of significant myelodys- of PDGFRA. PDGFRB or FGFR1. Some J:dycythaemic stages of PV is difficult p lasia gen erally indica tes a transition of cases with a mutation of JAK2 as a sole 1121 22 22241. Often, the PB smear in 6, 23, the disease to a more agg ressive, often genetic abnormal ity do not meet the cri- li.dI cases shows thromboc ytosis and terminal b last phase. If the initia l diag - teria for a specific MPN or any other spe- Iaiatlle neutrophilia. The haemog lob in nostic speci men has features of a myelo- ci fic disease ca tegory, and are thus best concentration may be normal, mildly d e- proliferative proces s that cannot be ca tego rized as MPN, U. eeasec or borderline incr eased . The 8M spec ifically ca tegorized , but shows bqJsy specimen frequently shows hyper- 10-19% b lasts in the PB or BM, the diag· Postulated ce ll of origin terlJiarityand often prominent megakaryo- nosis of an accelerated stage of an Haematop oietic stem ce ll. ClI= proliferation, with variable amounts of MPN, U, is appropriate, Irrmu notlistochem- Qa1Jlocytic and erythroi d prol iferation ical staining of the 8M biopsy sec tions for Prognosis and predi ctiv e factors 12216,2223,22241, If the guid elines suq- CD34 ma y be of diagno stic value in these In patients with the initial stages of an gested in the previous sections for each cas es by demonst rating increased num- MPN that is urctassmabie. follow-up stud- specdic MPN are carefully applied wi th ber s an d/or clusters of blasts 12216, ies performed at intervals of 4-6 mon ths ti:lSe attention paid 1 the megakary- 0 22221. If bl asts account for 20% or more wilt etten provide sufficient information for ocy£ morpholog y and histotopography, of the perip heral white blood cells or nu- a more precise classification {2216, 2222/. lOSt cases can be accurately assigned cleated 8 M cells in the initial specimen , Such patients in the early stages of dis-I 1I 8spedic subtype; but if not. the des- then the diagnosis is acute leukaemia , ease will have a prognosis similar to those• ."a1OO ot MPN, U is preferable until and the suggestion that the case may be of the group into which their disease follow-up data or adomonar lebo- a bl ast transformation of a previous but eventually evolves. Patients with advanced By studies provide evidence leading uncl assifiable MPN is appropriate, Myelo- disease in whom the initial proc ess is no 1)8 precise diagnosis. dysplastic features may appear dur ing k>nger recognizable due to 8M fibrosis or, lJe-stage disease. the BM specimens the natur al p rogression 01 an MPN even bla stic infiltration wou ld be expected to -eseal dense fib rosis and/or os teo-,e ~, indicating a terminal or without prior cytoreoucuve therapy. How - ever. if the initial pretreatment specimen have a poor prognosis.e ...m<lA stage, and distinction between demonstrates myelodysplasia , the diag- oost-polycylhaemic stage of PV nosis of a myelodysplastic syndrome or of Myeloproliferative neoplasm, unciasSlfiable 65
  • 65. Myeloid and lymphoid neoplasms B,J . Bain D,G Gilli landwith eosinophilia and abnormalities of H.-P. Horny JW. VardimanPDGFRA,PDGFRBorFGFR1Myeloproliferative and lymphoid neoplasmsassociated with rearrangernenl of PDGFRA.PDGFRB and FGFA1 constitute three rarespecific disease groups, which have ,sore sha red features and some that dif-fer. All result from lormalion of a fusiongene encoding an aberrant tyrosine ki-nase. Eosinophilia is characteristic but notinvariable. II has been established that, inthe case 01 POGFRA and FGFR t-relatedneoplasms. the cell of origin is a mutatedplu ripotent (lymphoid-myeloid) stem cell.It is possible that this is also true forPDGFR~relaled neoplasms, but this hasyet to be established.All three disorders can present as achronic myeloproliferatIVeneoplasm (MPN) ,but the frequency 01 manifestation as a . ..- ... .lymphoid neoplasm varies . The clinicaland neen ercoocer features are also in- •. 4,, . , ~fluenc ed by the partn er g ene involved . Inthe c ase of PDG FRA-related disord ers, "" f ig. 3.01 FIP1L 1-PDGFRA-ffllaled etvonic ~leu kaerlia. A PenpheraI blood IilmstIOlWIg Ihree rrlllder*fprese ntation is usua lly as c hronic eo sino- degranulated eosinopllils. Romanowsky stain. B Treph biopsy section. Abundanl eosinophils and eosIq)lli inep hilic le ukae mia (CEl) with promi nent precursors, Giemsa stain. C Trephine biopsy S&ClIOO. Abunda mast cells. many of wIit:tI are spindle-shaped, lllinvolve ment of the mast cell linea ge and Iormingsmalloose dosleB, Masteel tryplIS8 staining, 0 Trephinebiopsy section. CD25expression in tilemast CIksometimes of the neutr oph il lineage. l essoften , pr esent ation is as ac ute my eloid eosinophilia, Other patients have had CEL, molecular genetic analysis or both shouldleuka emia (AMl ) or precur sor-T lymp ho- precursor-B lym phoblastic leuka emia / be car ried out in all patients in whom MPNblastic lymphoma (T-LBL), in both instances lymp homa or AML. w ith eosinop hilia is suspected and alsowith ac companying eos ino philia , In the The importance of recog nizing these di s- in pat ients presen ting with an acutec ase of PDGFRB-related disea se, the fea- o rde rs is that the aberrant tyro sine leukaemia or lymphoblastic lymphomatures of the MPN are more va riab le but are kinase activity can make the d isea se with eosinophilia. Recognition of PDGFRAoften those of c hronic myelomonocytic responsive to tyrosine kinase inhibitors, related disease usually requires molecularleukaemia (CMML) with eosinophil ia, Pro- This hope ha s already been reali zed for genetic ana lysis, sinc e the majority ofliferation of aberrant mast c ells can again MPN with rearrangemen t of PDGFRA o r cases resu lt from a cryptic deletion,be a feature. Acute tran sformations that PDGFRB, whic h are resp onsive to ima- whe reas c ytogenetic anal ysis will revealhave been d escribed to date have been tin ib and some related ty rosine kinase the ca usative abnormal ity in the case ofmyeloid . In the case of FGFR r-reteteo dis- inhibitors . Similar specific therapy has not PDGFRB- and FGFR1-related d isease.ease, a lymphoma tous presentation is COOl- yet been de ve loped for FGFR 1-relale dmon, pa rticularly T-18L with accompanying disease. Rele va nt c ytogenetic analysis, Myeloid and lymphoidT~" 3.01 Diagnosticctitena of an MPN wilt1 eoslnophilia associated witt1 FIP1U -PDGFRA. neoplasms with PDGFRA AmyeloproIlferatMl neoplasm .",111 promnenl eosmoph~ia reanangement AND Presence of a FIPILl-PDGFRA fusion gene Definition The most common MPN assoc iated wll1l • Patients preserUlg witt1 aculemyekidledaema or tyr1lJhDbIastic ~ with8CJSinOPt*l and PDGFRA rea rrangement is that asSOCI- a FIP1L1.fOGFRA lusion geneare also aSSlgfllld tobs categoIy. ated with F1PIL l-PDGFRA formed as a ! II appropnate OI)IeaJar.-.alysis is not 1IYIilable.lhisliagnosis slJ:ll*S be suspected ilU1ere is. Pt-negalrve result of a cryptic de letiorl at 4q 121466l MPN lIiIlIh Ihe ~ teahns of chronic eosirq:lhIc leukaemia assooateeI WIfI ~, • (Table 3.0 1). Presentation is generally as marked ~ of 58I0OI YltaJfWI812. eIeYaliort of serum tryplase and incteasecI bone IlllWIlM mast llllI!. eEL but can be as AM L, T·LBL or bon68 Myeloid and lymphoid neoplasms with eosinophilia and abnormalities 01 PDGFRA . PDGFRB Of FGFRI
  • 66. smcuaneously (14691. Acu te transforma-tion can follow presentation as GEL.Organdamage occurs as a result of leukaemicinfiltration or the release of cvtokines. en -zymes or omer proteins by the eoeropnnsand possibly also by mast cells. The peri-pheral blood (PB) eosinop hil count ismarkedly elevated (in cases reported todale it has almost always been ~ 1.5x1rPlL)atthough it should be noted that. in someseries of patients . investigation was con-fined to patients with eosinophilia. There is ----no Ph chromosome or BCR-ABL 1 fusion , --gene. Except when there is transformation I~"!.-­kl acute leukaemia, there are <20% blastsfl the PB and bone marrow (8M), --- ~opi . .. . ,roo _ a 1,...... eEL_The provisional code proposed for the ~". _c:,........., I @ -=Iya&.fourth edition of IGOoO is 996513 ~~ nptIine b60CIaY Met 1n,"tiglClonbSynonymsChronic eosinophiliC leukaem ia: chron iceosinophilic leukaemia wilh FIPIL1-PDGFRA; myeloproliferat ive var iant ofthe hypereosinophilic syndrome. IEpidemiologyThe FIP1Ll ·PDGFRA syndrome is rare. It eel ~~~ ., t,G eis considerably more common in menthan women; the M:F ratio is - 17:1. Itspeak incidence is bet ween 25 and 55years (median age of onset in late 40s)with reported cases ranging in age from 71 77 years 1131). 0 --_.......... @ r.::==:=:::::-lEtiologyThe cause is unknown, althoug h severalcases have been reported following c yto-toxic chemotherapy 11 625, 2157) and a ~ --, (lncludiog f _ I ...u..tI.1(11 nut .... ~I. Hoi .... idiopathic HES Fig. 3.02 Flow diagram showing the diagnostic process in hypereosinophilia, e EL, chronic eosinophilic leukaem ia The definitivediagnosis is shown within blu circles/ovals, ecase of chronic myeloid leukaemia with aBCR·PDGFRA fusion gene also followedcombination chemotherapy 119061 . gastrointestinal symptoms 1 466 , 139 1, markedly elevated (2309). FIP1L 1-PDGFRA- 2309 1. The majortty of patients have associated GEL is very responsive to ima-Sites of involvement splenomegaly, and a minority have hepato- tinib , the gene prod uct being 100-foldGEL associated with FIP1L1-PDGFRA is megaly. The most serious cl inical findings more sensitive than BCR-ABl 1 1 466J.a multisystem disorder, The PB and 8 M relate to endomyocardial fibrosis, with en-are always involved , Tissue infiltration by suing restrictive cardiomyopathy. Scarring MorphOlogyeosinophils. and release ot c v tokmes and of the mitral/tricu spid valves leads to The most striking feature in the PB ishumoral factors from the eosinophil gran- valvular regurgitation and formation of in· eosinophilia. the eosinophils being mainlyuleslead to tissue damage in a number of tracardtac thrombi, which mav emtonze. mature with only small numbers of eosino-organs, but the heart, lungs , central and Venous thromboembolism and arteria l phil mveiocvtes or promyelocytes . Thereperipheral nervoussystem. skin and gastro- thromboses are also observed . PulrTl()l1ary may be a range 01 eosinophil abnormalities,intestinal tract are commonly involved . disease is restrictive and related to fibro- inclUding sparse granulation with clearT spleen is enlarged in the majority of he sis; symptoms inc lude dyspnoea and areas " cytoplasm, cytop4asmc vacuolation,patients. cough; there may also be an obstructive smalle r than norm al granules , immature element. Serum tryptase is increased granules that are purplish on aCinical features (> 12 ng/mJ). usually to a lesser extent Romanowsky stain . nuclear hyperseg-Patients usually present With fatigue or than in mast cell disease but with some mentat ion or hyposegmentation andpruritus, or with resp iratory. cardiac or overlap. levels of serum vitamin B12 are increased eos inophil size 1466, 23091 . Myeloid and lymphoid neoplasms associated with POOFRA rearrangement 69
  • 67. These chanQes may, however, be seen in cases of reactive as well as 01 neoplastic eosinophilia 11281 and, in some cases, of FIPIL I-PDGFRA·associated CEL, the eosinophil morphology is c lose to normal. Only a minority of patients have any increase in peripheral blast cells 123091.Neutrophils may be increased. while baso-phil and monocyte counts are usuallynormal 118541. Anaemia and thrombo-cytopenia are sometimes present. Any ts- Fig. ] .03 Myeloid neoplasm with eosinophilia associated WIlt! PDGFRB rearrangement Penpheral blood lWn dsue may show eosinophilic infiltration. and a palienl MIh 1(5;12) showing numerous abnoImaleosiIlOphis; eosmphis were 40% cIleukoc)1eS.Charcot-leyden crystals may be present.The 8M is hypercellular with ma rkedlyinc reased eosooprars and precursors. In Genetics Prognosis and pred ictive teetersmost cases . eosinophil maturation is or- Usually cytogenetic ana lysis is normal, Since FIPtL 1-PDGFRA-assoc iated GELderly, without a d isproportionate inc rease with the FIPIL I-PDGFRA fusion gene and its imatinib responsiveness werein blasts. but in a minority the percentage resu lting from a cryptic del(4)(q12). recognized lor the first lime only in 2003of blast cell s is increased. There may be Occasionally there is a chromosomal 14661. the Iong-Ierm prognosis is not yetnecrosis and Charoot-leyden crystals. par- rearrangement with a 4q12 breakpoint known . However. prognosis appearsticularly in those cases where the disease such as t(1:4Xq44:q12) 14661 or 1(4;10) favourable if cardiac damage has notis becoming more acute 14661. Bone mar- (q12;p1 1) /21631. In other patients there already occurred and imatinib treanre«rem mast cells are often but not always in- is an unrelated cytogenetic abnormality. is available. lmatinib resistance can de-creased on trephine biopsy 11163. 1688} e.g. trisomy 8, which is likely to represent velop, e.g . as a result of a T6741 mutationand mas t cell proliferation should be rec - disease evolution. The fusion gene can (which is equivalent to the T3 151mutationognized as a feature of FIP1L 1-PDGFRA- be detected by AT-PCA, nested AT·PeR that can occur in the BCR-ABL 1 gene)associated MPN. The mast cells may be often being required 14661 The causative 1466. 844} . Alternative tyrosine kinasesca ttered Of in loose noo-cot1esive clusters deletion can also be detected by fluores- inhibitors such as PKG412 and sorafeniborin cohesive clus ters {1163. 16881. Many cence in situ hybridization (FISH) analysis, may be effective in these patients 1468.cases have a marked increase in C025+ often using a probe lor the CHIC2 gene. 1297. 2 103}. Patients presenting as AMlspindle-shaped atypical mas t cells , and in which is uniformly deleted , or using a or T lymphoblastic lymphoma can achieveoccasional c ases morpho logical features b reak -apa rt probe that encompasses sustained complete molecular remissionare indistinguishable from those of systemic FlP tL 1 and PDGFRA. Since the maiontv of with imatinib 114691.mastocytosis. Aeticulin is increased 111631. patients do not have an increase of blastPatients presenting with AMl or T-l Bl cells or any abnor mality on conventional Variantshave had coexisting eosinophilia (PB counts cytogenetic analysis, it is usually the de- A number of possible mo lecula r variants1 4- 172x 109/ ) and in the majority of l tection of the F/P 1LI -PDGFRA fusion gene of F/P1L 1-PDGFRA-associated GEL havecases ore-extsunq eosino p hilia was also that per mits the definitive d iag nosis of a been recognized in wh ich there aredocumented (1469 1. myeloid neop lasm . Cytoge netic ab no r- other fusion genes inco rpo rating part of ma lities ap pear to be more com mon when PDGFRA. A ma le patient with imatinib-Cyt ochemi stry evolut ion to AML has occurred (1469 1 resp onsive CEL was found to have aCytochemical stains are not essen tial for K /F5B-PDGFRA fus ion gene assoc iateddiag nosis. The reduced g ranule conten t Postulated cell of origin with a com p lex ch romosomal abno rmalityof eosinophils can lead to reduced pe r- The c ell of origi n appe ars to be a p luripo- invol ving chromosomes 3. 4 and 10oxidase con ten t and inaccurate auto- tent haemopoietic stem cell able to give 119 79 1. and a female patient had ama ted eosino phi l counts. rise to eosmophtts and in some pa tients CDK5RAP2-PDGFRA fusion gene associ- neutrophils. rronocytes, mast cells. T cells ated with ins(9:4)( q33:q 12Q25) 123541. AImmunoph enotype and B cells {18541 . The detection 01 the male patient with t(2;4)(p24:q 12) and aEosmcptuls may show immunophenotypic fusion gene in a lineage does not neces- STRN-PDGFRA fusion gene 14971 andevidence of ac tivation such as expressionof C023, C025 and C069 11163}. The sarily correla te with morphological evi- dence 01 involvement 0 1 that lineage . ano ther with t(4; 12)(q2?3;p1?2) and an ETV6-PDGFRA fusion gene, both with the , (ma st cells in this syndrome are usually lymphocytosis. for example . is not usual, haematological features of CEL respondedC02-negative cozs-coense 11162} but even in those with apparent involvement 10 low-dose imatinib 14971. Esome times are C02-negative C025· of the B or the T lineage 118541. In Patients with t(4 :22)(q12;q1 1) and a Tnegative 114691 and occasionally C02· chronic phase disease, involvement is BCR-PDGFRA fusion gene, four cases a npositive C025-poSitive 11469J. In conp- predominantly of eosinophils and to a which have been described, have de- aanson , the mast cells 01 systemic masto- lesser extent mast cells and neutrophils. ease characteristic s intermediate betweer.cytosis are almost always C025-positive Acute phase disease may be myelOid or those of FIPIL 7-PDGFRA-associaled " rrand are C02-positive in about two thirds T lymphoblastic 11469}. eosinophilic leukaemia and those a /:of cases. BCR-ABL t-poseve chrcnic myeIogenec:l.lS70 Myeloid and Iymphotd neoplasms With eosinophilia and etoomannes of PDGFRA. PDGFRB 0 FGFR 7
  • 68. leukaemia; eosinophilia mayor may not Table 3 02 Diagnostc criteria of MPNaSsocl ted witll ETV5-POGFRB tusioo gene oroItIer rearrangement of PDGFRB abe prominen t 1162 , 765, 1906, 22661. Ac- A~~ , often -MIl ~eosilqlhIa fn:I ecreeres witt1 ~ orflUlX)tlsiscelerated phase 11621 and T 11 621 and B ANDlymphoblastic transformation 122661 have fntsence of 1(5:12)(q31""Q33;pt2)or a variant translocatiOn or,demonstrabor1 of an ETV6-PDGFRB fusionbeen report ed . The condi tion is imatinib- gene or of reBlfBngememof PDGFRBsensitive 11906, 2266/ . , Because t(5;ll)(q3t""Q33;p12) does IIOl always INd 10 an ETV6-PDGFRB fusion gene, rnoIei::uIM conlirmation is ~ (lesjrable If IlJClIe(Uar ana/ySiS is not avaiable. Ihis dtagnosJs shoj:j be suspected if there IS a fIl.Myeloid neoplasms with negative MPN asscrialed wi1tI eosirqIhiIiIlnd witha ~sIocaborl Wllh I 5q31-33 brealqloint.PDGFRB roanangement Table 3 03 f.Aljecu1ar variants of MPN associated WIth ETVUDGFRB Modified from It31) FUIlon V&I1tDefinitionA distinctive type of myeloid neoplasm t(1;3:5)(p36J)21;q33) WDR48-POGFRB caoccurs in association with rearrangement~ PCXiFRBat 5q31-33 (Table 3 .02) . Usu- d8r(1lll1 ;5)(p34:q33). GPfAP1-PDGRFB ca dert5)1(1:5)(p34:ql5).aIy there is t(5 ; 12XQ31 - 33 ;p 12) with for- der(11 )ils(11;5Xp12:ql5q33)malion of an ETV6-PDGFRB fusion gene1 11341. In l/OCOITITlOfl variants. other 812. 1(1:5)(q21;q33) TPMJ.POGFRS ca"ansIocations with a 5q31-33 breakpointlead to the formation of other fusion genes, 1(1:5)(q23:q33) POE4DIIPOGFRSsse incorporating part of PrX;FRB (Table l(4;5;5)(q23:q31;q33) PRKG2-PDGFRB3.03). In cases with t(5 ;12) . and in thevariant rransiocatcne. there is synthesis l(3;5)(pll·25;q3t-35) GOtGA4-POGFRB~ an aber rant, consti tutively activated ty- l(5:7)(q33;q1t .2) HIP1.pf)GFRB CMML WIth eosirloptlia!OSine kinase. The haematological featuresare most often those of CM ML (usually l(5:10l(q33:q21) CClJC6.PDGFRB aCMLWllh eosinoph6a, MPD with eosinophNWith eosinophilia) but some patients have t(5;ll)(q31.J3;q24) GIT1.p()GFRB eElbeen charac terized as atypical ch ronicmyeloid leukaemias (aC ML) (usually with l(5;14)(q33:q24) NIN.PDGFRB PlHlega1ive CML (13% eoV1ophils)eosinophilia), CEL and MPN w ith eosino- t(5;t4)(q33;q32) KlAA1S09-POGFRB CMML wrlh eosinophiliaphilia 1131. 20851 Single cases have ;been reported of AML. probably superim- 1(5;15){q33:q22) TP53BP1-PDGFRB Ph-negabveCML with prominent eosinoptlIa posed on ch ronic idiopathic my elofibrosis t(5:16)(q33:p1J) NDE1-PDGFRB CMML 12245). and of juve nile my elomon oc ytic eukaemia 115 13J, the latter associated t(5:17)(q33:pt 3) RABEP1 -PDGFRB CMML /jith a variant fusion gene . Eosino philia is usual but not inva riab le 12085 1 Acute t(5;17}(q33: pl1.2) SPECC1 -PDGFRB JMMLsensiorrnaton ca n occur, ofte n in a rela- aCML. alypical chronicmyeloidl6ukaemia; CEl , chrooic eosinophilk:leu kaemia: CML, chronic myeloid tively short period of tim e . MPN with leukaemia: CMML, chronic myelornonotybc leukaemia: JMML, juvenile myelomonocytiC leukaemia: MPOIMOS, PDGFRB rearra ng eme nt is sensi tive to myeloproliferativeJmyeioctysplastic syndrome: MPN, myeloproliferative lleOpIasm. tyrosine kinase inhibitors such as imatinib;64).ICD-O codeThe provisional code pro posed for thefoorth editio n of ICO- O is 996613. SyronymChronic mvetomonocvnc leukaemia with!IOSinophilia associated with t(5 ;12) .-"ogy T!IIS neoplasm is considerab ly more com- ~ in men (M :F.,2:1) an d has a wide age range (8-72 yea rs) with the p eak rcoerce being in mi ddle-aged ad ults; reoen age of onset is in the late 405 00lS1. • rl _ Fig. 3.04 Myeloid neoplasm wItI ~ associa1ed wilh PDGFRB ~ Trephine biopsy sedion In:lm a pallllIt WIth 1(5;12) showing a mar1o.ed increase in eosWlclphiII. Myeloid and lymphoid neoplasms associated W Ith PDGFRB rearrangement 71
  • 69. Sites of involvem ent Geneti c s VariantsMPN associated with t(5; 12Xq31-33;p12) Cytog enetic analysis usually shows t(5;12) A number of molecular variants of M PNis a mul tisys tem disorder, The PB and BM (q 31-33 ;p 12 ) with the translocation with ETV6-PDGFRB fusion have beenare always involved, The spleen is en- result ing in formatio n of an ETV6-PDGFRB reported 1131, 20851. In addition, a patie!tlarged in the majo rity of pa tients. Tissue fusion gen e {8 12/ (p re viously known as who acquired eosinophilia at relapse (jinfiltration by eosmoctats and release of TEL-PDG FRB), In one patient ETV6· AML was found to have acquired 1(5:14cvtounes. humoral factors or granule PDG FRB resulted from a four-way trans- (q33;q22) with a TRIPl1-PDGFRBfcontents by eosinophils can contribute to location, t( 1; 12;5 ; 12 )(p 36 ;p 13;q33;q24) gene. A number of other patients ha",tissue damage in a number of organs. {489J, and in anomer occurred in rearrangement of PDGFRB but With association with ins(2 ; 12)(p21;q?13q?22) second gene involved being unl<.novo1l.Clinical features 15121. The 5q breakpoint is sometimes Complex rearrangements appear to bePatients often have splenomegaly, with assigned to 5q3 1 and sometimes to common (e .g. a small inversion as~.hepatomegaly being present in a minority. 5q33, although the gene map loc us of translocation) 120851 Because of the .Some patients ha ....e skin infiltration and PDGFRBgene is 5q31·32. apeutic impl ication s, FISH (break·~some have cardiac damage lead ing to Not all translocations characterized as FISH with a PDGFRB probe) is indical d ecardiac failure . Serum tryptase may be t(5 ;12)(q31 ;p13) lead to ETV6-PDGFRB in all patients with a presunptivemildly or moderately elevated The great fusion . Cases without a fusion gene are of MPN who have a 5q31-33 breakma;ority 01 patients who have been not assigned to this category of MPN and. particularly. but not only. if there ,treated with erenmo have been found to importantly. are not likely to respond to eosinophilia. However, FISH analysisbe responsive. imatinib; in such cases an alternative not always demonstrate rearrangemercd Ieukaemogenic mechan ism is upregulation PDGFRB, even when it is detectableM<Kphology of mterleukin 3 (IL3) 146 71 AT-PeA. using . Southern Blot analysis 120851. MoIect.iJThe white cell count is increased . There primers suitable for all known break- analysis is not indicated if there ismay be anaemia and thrombocytopenia points, is therefo re rec om me nd ed to 5q31-33 breakpoint on classicalThere is a ....anabre increase of neutro- confirm ETV6·PDGFRB {498 / but if genetic analysis since all cases rephils . eosooonne. rrooocvtes and eosino- molecular analysis is not available a Irial to date have had a cytogenetically de-phil and neutrophil precursors. Rare ly. of imatinib is justi fied in patients with an lectable abnormality.there is a marked increase in basophils MPN assoc iated with 1(5; 12).{23551. The 8M is hype rcellu lar as a resultof active granulopoiesis (neutrophilic and Postulated cel l of origin Myeloid and lymphoideosinophilic). Bone marrow trephine b iopsy The cell of origin appea rs to be a multi-may show, in ad d ition , an increase 0 1 mast neoplasms with FGFRI po tent baemocorenc stem cell , which iscells and these may be spindle-shaped able to give rise to neutrophils, monocytes. abnonnalities1503,23551. Bo ne mar row reticulin may eosinophils and probably mast cells,be inc reased 123551. In c hro nic p hase Definitiondi sease, the blast cell co unt is less than Progn osis and predi c tive factors Haematoroqrce! neo plasms with FGFRJ20% in the PB and 8 M. Pre- imatinib, the med ian survival was less rea rrangemen t are hetero geneous.They than 2 yea rs, Ther e are not yet re liab le are de rived from a pluripote nt baemaioCytochemistry data on surviva l of imatini b-treated poietic stem ce ll, altho ug h in differetlThe eos inop hils, neut rophile a nd mono - pat ients, but in a small series (10 patients) patients or at d ifferent stages of the diseasec ytes show the expecte d c ytoc hem ical the med ian surviva l was 65 mont hs 1 5121 . the neop lastic ce lls may be precursareacti ons for ce lls of these lineages, Med ian survival is likely to im prove as cells or mature ce lls. Presentation call be patients are recog nized and sta rted on as an MPN or, in tra nsfor mation, as AMLImmunoph enotype approp riate treatment at d iag nosis rather T or 8 lineage lymphoblastic lymptloolQlImmunop henotypic analysis of the mast than when c ardi ac d ama ge or transfor- leukaemia or mi xed p heno type acutecells has show n exp ression of C02 and mati on has alread y occurred leukaemia (MPAL) (Tabl e 3.04).C025, as is also obse rved in the majori tyof cases of ma st cell disease [23551. ICD-O code The provisional code proposed fOf tl"E fourth enuon of ICO-o is 996713.Table 3.04 Diagnosbc 0Itetia of MPNor actIIe leuk.aerria associated withFGFRf rearrangement Synonyms A myeIoproIlleralive neoplasm lMlh promIfIent eosmpI1E and sometines withneutrophilia or rTW:IAClC)Iosi 8p 11 myeloproliferative syndrome, 8p11 OR stem cell syndrome, 8p1 1 stem eel Acute myebd leukaemia or preanor T or preanor EkeII tymphoblasliC ~ {~ <eII leukaemiallymphoma syndrome. associated with periphetaI blood or bone JTIilITlIW eosonophIia) AND EpklemKllogy Preseoce r:A .8;13)(P11;q12) or. v;nnlJallsb.. boil!eadlng kl FGFRf~ delrorkStJaIed in a This neoplasm occurs across a wide age ITI)8Ioid eels, ~sts or boItl range (3-84 years) but most patients are young . with a median age of onset iJi72 Myeloid and lymphoid neoplasms With eosooobne and abnormalities 01 PDGFRA. PDGFRB Of FGFRI
  • 70. aroun d 32 yea rs {1354 1. In contrast 10 Iymphoblasts and myeloblasts in cases in Table 3.05 Chromosomal rearrangements and fusionMPN with rearrangemen t of POGFRA and transformation. Basoph ilia is not usual but genes reported in MPN associated wiltl FGFRtPDGFRB, there is only a moderate male patients with BCR-FGFR1 fusion may rearrangemenl·. Modrtied from (1311.predominance ( 1.5:1) have basophilia {18791. An association with Cytogeoetica M~laf geoetic:s N polycythaemia vera has been observed in 1(8; 13)(pl l;q12) ZNFI98-FGFRSites of involvementTissues primarily involved are 8M , PB, three patients with t(6;8)1FGFRIOP I-FGFRI fusion 11770, 23401 . t(8:9Kp11 ;q33) CEPf1O-FGFR1 " •lymph nodes, liver and spl een. lym- T precursor lymphoblastrc lymphomaphadenopathy is the result of infiltrationbyeither Iymphoblasts or myeloid c ells. charact eristically shows eosinophilic infiltration within the lymphoma. t(6:8l(q27:pl1-12) 1(822 l(pl1;ql1) FGFRIOP1.FGFR1 BCR-FGFR1 • 5 Cases should be classified as leukaemia!Clinical features lymphoma assoc iated with FGFR1 (l .8l(q34:pl1 ) TRJN2.f.FGFRJSome patients present as lymphoma with rearrangement, followed by further details 1(8.11)(pl1:Q23) lrlY018A-FGFR1mainly lymph node involvement . while of the specific p esenatco. e.g. "~others present with myeloproliferative lymphoma assoc iated with FGFRI 1(8:19)(pl2;q13.3) HERVK-fGFR1leatures. such as splenomegaly and rearrangement/chronic eosilophilic IelJ<ae. n(12:8)(p11;pl1p22) FGFR10P1-FGFRfhype rmetabolism. and yet others wilh mia, T precursor IyrrVlobIastic lymphoma.features of AML or myeloid sarcoma 13. or "leukaemia/lymphcma associated with • tI adclillon, FGFRJ fl!IilfTiIliQt!ilelt has been ku1d II1006. 13541. Systemic symptoms such as FGFRI rearrangemenl/myeloid sarcoma". iISSfJciaIio. will ~: 12l(p11;q151aocl.8:17XP1l;q25)fever. weight loss and night sweats are but h suspected IwoIYement d FGFRt 1I1(8:tl ) (p11,pt5) wasnot confrmed.otten present 11311. Cytochemistry I rvrtln ~ tern MaI::OoniIId iIl"Il Cross (1354). Neutrop hil alkaline phosphatase score is ~ often low, but cytochemistry is not impor- Presen tation may be as CEL, AML, tant in the diag nosis. Postulated cell of orig in T-LBL or. least often. precursor B lympho- The cell of origin is a pluripotent tymphoid- blastic leukaemiallymphoma . Cases 01 Immunophenotype myeloid naema topoietlc stem cell.acute leukaemia/lymphoblastic lymphoma Immuno phenolypic analysis is not usefulmay be of mixed phenotype . In patients in chronic phase disease, but is importa nt Prognosis and pred ictive factors who present with CEL. there may be sub- to demonstrate the T or B lineage 01 The prognosis is currently poor. There issequent transformation to AML (including precursor Been or pr ec ursor r-ceu no estab lished tyrosin e kinase inhibitormyeloid sarcoma), T or B lineage lympho- leukaemiallym phoma. therapy for MPN with FGFRI rearrange-blastic leukaemiall ymphoma or MPAL. ment. althou gh PKC 142 was effect ive inLymphoblastic lymphoma ap pea rs to be Genetics one case 14 001. Interferon has induce d arrore common in patients with t(8;13) than A var iety of transloca tions with an 8p 1 t cytogene tic response in several pa tientsin those with variant transiocatons 113541. breakpoint ca n underli e this syndrome, 11354. 14021 Until specific therapy is .Patients who present in chronic phase Secondary cytogene tic abn ormalities develop ed. haematopoietic stem cellusually have eosinophil ia and neutrophilia occu r, among wh ich trisomy 2 1 is most tran splantation should be considered .and, occasionally. mono cyto sis. Those often obser ved. Dependi ng on the partner even in those who present in chron icwho present in tran sformation are often chromoso me, a variety of fusion gene s phase.also found to have eosinop hilia, Ove rall, inco rpo rating part of FGFR1 are formed .about 90% of pat ients have PB Or BM All fusion genes encode an abe rrant tyro-eosinophilia (1354). The eosinophils be- sine kinase (Tab le 3,05)long to the neop lastic clone, as do the Myeloid and lymphoid neoplasms associated WIth FGFRI abnormalities 73
  • 71. CHAPTER 4 Myelodysplastic/Myeloproliferative Neoplasms Chronic mye lomonocytic leukaemia Atypical chronic myeloid leukaemia. BCR-ABL 1 negative Jwenile myelomonocytic leukaemiaMyelodysplasticlmyeloproliferative neoplasm. unclassifiable
  • 72. Chronic myelomonocytic leukaemia A. Orazi J. M. Bennett U. Germi ng A.D. Brunning B.J. Bam J . ThieleDefinitionCIvLric~ IeU<aenia (CMML)is a clonal baematopoletrc mal ignancythat is characterized by features of both a 2. No ~ cf1romosomeor BCR-A8L11usion genemyeloproliferative neoplasm and a mye lo-dysplastic syndrome. It is characterized 3, No rearrangement of POOFRA or POGFRB (sllouldbe spealicaRy e~duded 11 cases Wlth eosinophialby : 1) persistent monocytosis >1x 1()9/L in 4 Fewer than 20% blasts" in the blood al(j in ee bone marrowthe peripheral blood (PBl; 2) absence ofa Philadelphia (Ph) ch romosome and 5. Dysplasia In oneor more myeloid lineages. If myelodys~asia is absent or minimal. the diagnosis of CMM,.BCR-ABL 1 fusion gene; 3) no rearrange- may stil l be made iflhe other requirements aremet. andment of POGFRA or PDGFRB (should be • anacquired, ctooa l cylogenelic or moleculargenetic abnoonality is present in thehaemopoietic cels. r:r lspecifically exclude d in cases with • the monocytosis hasp&rSisted forat east 3 months andeosinophilia); 4) lewer than 20% blasts • aijother causes 0( monocytosis have been e~duded(promonocyles are considered as blast • Blasts irl<:IWe myeloblasts. monobIasts and prornotlOC)le5. Promonocytes owe monocytic precursors WI1Ilequivalents) in the PB and bone marrow ab.IIdallt light grey or sIif1Iliy besophilic cytoplasmwitha lew scattered. h liIac-<::oIoIJ-ed p1UIes. finely-(8M) ; and 5) dysplasia involvi ng one or dislrtluled. sWied nudear etwomabn. variably prominent nudeoIi. WId delicale nud8arloIding oroeasilg. rdmore myel oid lineages. Howe ver, II c on- in tIIisdassilicaliorl are equivalenl lO~. AbnormaIITIClIIOCy1eS wnen can be present baCh ti the ~vinc ing myelodysplasia is not pre sent, the blood and bone marrow are excluded from lhe blastCCUIIldiagnosis of CMML can still be mad e ifthe other requ irements are mel, and anacqu ired. clonal cytog ene tic or molecular neoplasms. JAK2 V617F mutation is uo- at dia gnosis is 65--75 years. with a malegenetiC abnormality is present in the 8M ccmmon in CMML 11058. 20821· predominance of 1.5-3:1 148. 683. 777cells . or if the monocytosis has per sisted 2047.21021 ·for at least 3 mon ths and all other c auses ICD-Ocode 9945/3of monocytosis. such as the presenc e of Etiologymalignancy, infection or inflammation, Epidemiology The etiology of CMML is unknown. 0CCu-have been excluded, CMML is further There are no reliab le inc id enc e data for penona t and environmental carcinogenssubdivided into two subsets. CMML· 1 CMML. because in some epidemiolog ica l and ionizi ng irradi ation are possibleand CMML·2 , depending on the number surveys CMML is grouped with chronic causes in some cases 1108. 20261 .of blasts plus promonocytes in the PB and myeloid rewaemras and in others isBM. The clinical, haematological and mor- rega rded as a myeioovsptasnc syndrome Sites of involvementphological features of CMML are hetero- (M OS) 108] In one stud y in which CMML The PB and BM are always involved. Theg eneou s, and vary along a spec trum from accounted for 31% of the cases of MOS. spleen. liver. skin and lymp h nodes arethepredom inantly myelodys plastic to ma inly the incidence of MOS was estimated to most common sites of extramedu llarymyeloproliferative in nature. In contrast with be approximately 12,8 cases per 100 ()(X) leukaemic infiltration 148. 683, 777).the BCR·ABL 1negative myeloproliferative pe rsons per year (2414). The median age76 Myelodysplastic/myeloproliferative neoplasms
  • 73. Clinical features from 2 to 5 x10~/L, b ut may excee d (777, 1396. 164 51 . Neutrophil precu rsors Inthe majority of patients, the white blood 8Ox 1()91l [48. 683, 1396, 14711 Monoc ytes . (promyelocytes, myelocytes) usually ac- cell (WBC) count is increased at the time are almost always > 10% of leukoc ytes count for < 10% of the leukocytes 1189, of diagnosis. and the disease appears as 189.20031 . The monocytes generally are 2003 1 Dysgranulopoiesis. including neu- . an atypical myeloproliferative neoplasm. mature. with unremarka ble mo rphology. trophils wi th hypolobated or abnormally Inother patients, however, the WBC is nor- bu t can exhibit abnormal granulation, or lobated nuclei or abnormal cytoplasmic mal or slightly decreased with variable unusual nuclear lobation or chrom atin granulation . is present in mos t cases , but neutropenia and the di sease resembles pattern 111851. The tatter cells are best may be less prominent in patients with MOS. The incidence of the most common termed abnormal monocvtes -a desig- leukocytosis than those with a normal or presenting comp laints of fatigu e, weight nation used to describe rronocvtes that low wac 1185, 13961 It may be difficult . css. fever and night sweats is similar in are immature, bu t. in com parison to in some c ases to distingu ish between re two groups 01pa tients. as is the rate of promonocytes (and monoblasts). have hypogranular neutroph ils and dysp lastic otectooand of b leed ing due to thrombo- denser chromatin, nuclear c onvolu tions moooc vtes. Mild basophilia is sometimes cytopenia 1 48, 683 , 777, 2047 , 2 1021. AI· and folds, and a more gre yish cytoplasm , present. Eosinophils are usually normal or ilough splenomegaly and hepatomegaly Blasts and promonocytes may also be slightly inc reased in number, but in some rnirf be present in either gr oup, they are seen , bu t if the sum of blast s plus the cases eosinophilia may be striking. CMML more frequent (up to 50%) in patients with promonocytes is 20% or more , the d iag- with eosinophilia may be diagnosed when leukocytosis 177n nosis is AML rather than CMML. Other the criteria lor CMML are present. but in changes in the PB are variable . The wac addition the eosinophil count in the PB is Morp/loklgy and cytochemistry may be normal or slightly decreased . with 2: 1.5xlQ1JIl. Patients in this category ma y Peripheral blood monocytosis is the hall - neutropenia, but in nearly one half of hav e complication s related to the mark of CMML. By definitIOn, monocytes patients it is inc reased due not only to degranu lation 01 the eosinophils. These are always >lxl Q91l and usually range monocytosis bu t also to neu troph ilia "hypereosinophilic " cases of CMML may f1. U 2 Chn:nc myeIomonocytic IeukaenU-l. The degree of ~s, neutrr.optMia and dysploIsia is YiWiabIe .. CUt.4L. A The ..... bIoocI eel Cl:Ullis eIINaIed wiIh rnirImaI ~ in !he ~ series. B A noonaI wtJIe bIoocI eel axn WIth absokJte monocytOSis. ~ and dysgrarUopoiesls. C A bone marrow biopsy splDnen Inlm a ..,.. . CJM..·1. Oftsn, " grarUoqIlc WI.-u"" ~ is mosl obYil::lIJs lin se biopsy ~, iWllI monocyI8S may nol be rNliIy appreoaIed. D The tllded ru:IeIlnl dek:aIe .... c:tttInRn em..... iiIic fA monocyI8S CM be appreciated IIIIOIQ 1he~. Chrorllc myelornooocylic Ieuka8ffila 77!
  • 74. closely resemble cases of myeloid neo- A mild to moderate increase in the amount the presenting manifesta tion of CMML plasms with eo sinophilia associated with of reticulin fibres is seen in the 8M of Blast cells plus oromonocvtes usually specific cytogenetiC/mol ec ular genetic nearly 30% of patients with CMM L 114061. account for fewer than 5% of the periphera; abnormalities involving POGFRA or Nodules c omposed of mature p lasma - b lood leukocytes and fewer than 10% ci PDGFRB genes. for which suc h c ases cytoid de ndritic c e lls (plas mac yto id the nucleated BM cells at the time of should always be exam ined . These d isor- monocytes) in the BM b iopsy have been d iagn os is. A higher number of blasts der s are con sidered sep arately from reported in 20% of cases 116491 These . (p lus promonocytes) than this may ident4y CMML. Mi ld anaemia . etten nor mocytic cells have round nuc lei. finely d ispers ed pat ients who have a poor prog nosis or a but som etimes mac rocytic. is c ommo n. chromatin, inconspicuous nuc leoli and a greater risk of rap id tran sformation toPlatelet counts vary, but moderate thrombi> rim of eos inop hilic cytop lasm. The cyto- acut e leukaemia {48. 682, 683. 833. 2102.c yto pen ia is often pre sent. Atypical , large p lasm ic membrane is usua lly d istinc t. 2 170. 24431. Thus. it is recommelldecl platelets may be ob served 148. 13961· with we ll-defined cyto plas mic borders. that CMML be furt her d ivided into twoThe BM is hyperc e llular in ove r 75% of This imparts a c ohe sive ap pearanc e to subcategories. dependil"lQ on the runt:lEJcases. bu t rorrrcc enorer and even hypo- the infilt ratin g c ells. Apoptonc bodies. of blasts (plus promonocytes) found ilc ellula r sp ecimen s also occur (1471, often within star ry sky testrocvtes. are PS and 8M . as follows :21021. Granu loc ytic prol iferation is often frequently pre sent. The rela tionship of thethe mos t striking find ing in the BM biop sy plasmacytoid dendritic cell proliferation 1 0 CMML- 1but an increa se in erythroid pr ecursor s the leuka emic ce lls has been consider ed Blasts (including promonocytes) <5% r:may be seen as well (189. 14711. M0no- uncertain 1120, 655 , 895 , 9671. A recent ee PS , <10% in the BM ;cyt ic proliferation is invariably present. but study. however. has show n that they arecan be d ifficu lt to appreciate in the biopsy c lon al. neo pl astic in nat ure , and closely CMML·2or on 8M aspirate smears. Cytochem ica l related to the associated myeloid neo- Blasts (incl uding promonocytes) 5-1 9and immunohistOChemicalstudies that aid plasm 123351. in the PB or 10- 19% in the 8M . ex Itte1in the identificatiOn of mcoocvtes and their The splenic enlargement in CMML is Auer rod s are present irrespective of theless mature term s a re strong ly recom- usua lly due 10 infiltration of the red pu lp b last p lus p romonocyte cou nt.mended when the d iagn os is of CMML is by leukaemic cells. Lym phadeno pa thy issuspected 121701· Dysqranulcpoiests. uncommon, bu t when it occurs. it may The value of this approach has been re-similar 1 that found in the blood. is pres- 0 signal transfor mation to a more acut e cently con firmed 17801.ent in the 8M of most panent s with CMML. phase. and the lym ph node may show Cytoc hemic al or immunop henotypic stud-and ovsevmroooesrs (e.g. megaloblastic d iffuse infiltration b y mye loid blasts. ies are strongly recommended wheneverchanges, abnormal nuclear contours. ring Sometimes, there is lymph node and (les s the d iagnosis of CMML is c onsideredsrderoblasts) is observed in over one ha lf commonly) sp len ic involveme nt by a When performed on P8 and 8M aspirateof patients 177 7, 1396 , 147 11 . Micro- diffuse infiltration of plasmacytoid dendriti c smears. alpha naphthyl acetate esterasemegakaryocytes and/or meqekervccytes cells. In some patients generalized lympha- or alpha naphthyl butyrate esterase, usedwith abnormally lobated nuclei are found denopathy due to tumou ral prol iferations alone or in combination with naphttd-in up to 80% of patients [1396. 1471 1. of plasmacytoid dendritic ce lls may be ASD-chloroacetate esterase (cbioroacetaeIA;. 4.03 Chronic myelomonocytlc teokaemia-2. A Blood smear from a newly ~ patient. 0C:casi0naI bl9:sls W8f1l noled.,!he perVleIaI blood smear B Bilpsy~ .. .same palJefW. The ImaIJ.ny of !he ba1e fllamlW BIemenIs c:ar1 be rea:iIy appreciated. C BIasts.-.d pIOflIOfIOC) ICCOUIC lor 12".110 of !he IfllIm)fr eels (~ ~78 Myelodysplasticlmyeloproliferative neoplasms
  • 75. esterase, CAE) is extremely useful to as-sess the monocytic component.Inmunophenotype The PB and BM cells usually exp ress theexpected myelomo noc ytic antigens, suc hasCD33 and C013, with variable exp res- sion of C01 4, C068 and C064 1243, 1377, 24421 The PB and BM monocytes .often express aberrant phenotypes with:...oar more aberrant features by flow cvto- F"tg.4.04 Onncmyelomooocylic leukaemia, Some dl98801fibrosrsmay beseen in upb3O"1i 01 cases. A,8 Thesemetric analysis. Some, such as decreased pl1oklmicrographs 1ustra1e retiaJIin fibnls$ in a mafTllW blopsy specimen 01 a pabefIl WIIt1 CMML.expression of C0 14 , may reflect relativerronocyte immaturlty_ Other aberrantcharacteristic s include overexp resscn ofC056, aberrant expression of C02 orcecreesec expression of HLA-OA, C0 13,C015. CD64 or C036. There may be aber-rn phenotypic features on maturing gran-ulocytic cells and neutroonas may alsostlCM aberrant scatter properties . An rceaseo percentage of CD34 + cells or anemerging blast population with aberran t 1.rrrnunophenotype has been associated ,8tilth early transfor mation to acute Fig, U 5 CI.-onic myelornonocytIc leukaemia ANodI.*s COflIPOMd 01 pIastr1ac:ybd tter01tiC eels in the bone RIiIr- eukaerma (AML) 1626. 2442 , 24591. row 01 a patient WIIt1 CMML. B com is posilMIin pIasmaqtid dendriIic eelsIrrmunohistoc hem istry on tissue sec tionsb the identi fication of monocytic cells is mutations of RAS genes at diagnosis or is 20-40 months {48. 682 , 683. 777 , 779.-etanvelv insensitive as compared with dunnq the d isease course {1686, 2 118, 833,2047,2102,2170.2443 1_Progressioncytochemistry or flow cytometry. The most 24171- The approp riate categorization of to A ML occurs in approximately 15-30%reliable marke rs are CD68R and CD l63 baematoroqrcat neo plasms associated of cases. A num ber of clinical and1 1649J. Lysozyme used in conjunction w ith isolated isochromosome 17q is un- haematological pa rameters, includi ngwith cytoc hemistry for CA E can also faci l- certain at this tim e. Although a p roportio n splenomegaly, seve rity of ana emia and~ate the id entifica tion of monocytic cells, 01c ases meet the crite ria for CMML, others degree of leukocytosis, have been re-...nich are lysozyme- positive but negative may be more ap propriately ca tegorize d ported to be important factors in predict-lor CAE, in contrast with the c renulocytrc as MDS/MPN , uncrassmabre {708 . 14371- ing the cou rse 01the di sease . However, inprecursor ce lls, wh ich are pos itiv e for Abnormal ities of 11q 23 are unc ommon in virtually all studies, the percentage of PBbolh, An increa sed perc entag e of C0 34 + CMML, and instead suggest the diagnosis and BM blas ts is the mos t important fac-cells detected by immunohistochemistry 01 AML. tor in de term ining survival j48 , 480 , 682,has also been ass oc iated with tran sfo r- Cases of MDS/MPN with eos ino phi lia 683 , 777 , 780, 833, 2047, 2102 , 2170 ,mation 116491 . associated with t(S;12)(q31 -33;p1 2) and 2443 ).The plasmacytoid d endritic cells associated an ETV6-PDGFRB fusion gene, whic hIIithCMML have a c haracteristic immuno- were formerly incl uded in the CMMLpeeootype. They are positive for C 0 123, c atego ry, a re no w co nside red a d isti nctC D14, C0 43, C068, C 068R, C 0 4SAA, en tity, Cases resembling C MML mayC033 (weakly) and CD4. Granzy me B is express the p1 90 BCR-ABL 1 Isotorm andalso regularly exp resse d. but TIA 1 an d should be c lassified as ch ronic myelo-perforin are not. Variable C056 expression g enous leukaemia (CM L). Thus, if ais seen in a minor ity of the cases, whi le t(9 ;22)(q 34 ;q 11) is not detec ted by cyto-tceu-assoctateo an tig ens suc h as C02 g enetic analysis it is insufficient 10 use!Id CDS can also be present. only PeA analysis for the presence of p 210 to exclude CML.GeneticsCblal cytogenetic abnormalities are found Postu lated cell of originin 20-40% of pat ie nts w ith CMML, but Heerropoeuc stem cell.rme is specific 148, 683 , 684 , 777 ,867,2102, 2170, 2260 1_ The most frequent re- Prognosis and predictive factors:urng abnormalities include +8. -7/deI(7q) Survival of patients with CMML is reportedind structural abnormalities of 12p. As to vary from one to more than 100 months,many as 40% of patients exhibit point but the median survival time in most series Chronic myeklmonocytic IeukaerTlla 79
  • 76. Atypical chronic myeloid leukaemia, JW, Vardiman J.M. BennettBCR-ABL 1 negative B,J, Bain R D , Brunning J , ThieleDef inition Table • •02 Dl3QOOSoc critenalor at)1Ial dlronic myeloid leuUemIa, BCR-ItBL nega!lYe (acML).Atypical chronic myeloid leukaemia. ~ t*;lod Ieukocylosi$ (WBC 2: 13alO1l) cl.Ie 10IllCtlliIsed runbers 01 neutn;lp/iIs arKI theirBCR-ABL 1negative (aCMl) is a leukaemic prewrsor5 WIth prominent ~disorder with myelodysplastic as well as NoPh dlromosome or BCR-ABI..1 fIlSIOIl genemyeloproliferative features at the lime of NorearrMgBIIlllI 01 PDGFRA or POGFRBinitial diagnosis. It is characterized by Neulrophi prectJS(n {pfomyelocyles, myeIocyles,~) ~1 0% 01 leukocytesprincipal involvement of the neutrophil lin-eage with leukocytosis resulting from an hhnaIlIbsokIIe ~ : b9soptlis USUIIy 4"4 0I1IIukocylesincrease 01 tnOfphologically dysplastic Ncor IIIIIIirrIClI absoUe~ ; lMllOC)1eS <101t oI~neutrophils and their precursors. However,mullilineage dysplasia is common and ~arbone mafTtMwiII~ pi" . dysplasia n h etyflroict and megakaryocyIc Irl9Iges and ~~. W!ltl or wrtloulreflects the stem cell origin 01 aCML. The less than m bIiIsts n fie blood and n h bone rr8lUWneoplastic cells do not have a BCR·ABL 1fusion gene. counts in excess 01 3OOx1091l 1266, 928, common 1189 , 928,1396,20031 .ICD-<l code 987613 1208, 1396 ,20031. Blasts are usually less The BM biopsy is hypercellular due to an than 5% and always less than 20% 0I1eu~ increase 01 neutroph ils and their pecesosSynonym . cvtes. Neutrophil precursors (promyeloc- Blasts may be modestly inc reased 111Atypical chronic myeloid leukaemia. vtes. rnveiccvtes and metamyelocytes) number, but are always less than 20%: usually comprise 10 - 20% or more of the large sheets or clusters of blasts are rICKEpid emiology leu kocyte d ifferent ia l. Although the ab- present. Dysgranulopoiesis is a constantThe exact incidence of aCMl is not krlOWn, solute monocyte count may be increased, find.ng and the changes in the neutroptilbut is reported to be only 1- 2 cases for the perc entage of rnonoc yte s ra rely ex- lineage observed in the 8M are similar toevery 100 cases of BCR·ABL 1 positive ceeds 10. Baso p hilia may be observed those described for the blood, Megakaryo-C ML 1200 31. Patients with aCMl tend to but is no t prominent 1189 . 266. 928. 1396 . cvtes may be decreased. no rmal or in-be elderly. In the few series repo rted to 20031 The ma jor feature that character- . creased in nu mber, but in most casesdat e, the med ian age at di agnosis is the izes aC ML is ovsqranctoooese. which is some oysmeqakarvopoiesrs is presentseve nth or eighth d ec ad e of life bu t th e often pronounc ed , Ac qu ired Pelger-Huat or including sm all me gaka ryocytes andd isea se has been reported in teen ag ers othe r nuc lear abn or malities, suc h as ab- mic rorreqakarvocytes and/or megakaryo.as we t11266 , 928, 1208, 1396,20031 , The norm ally clumped nu c lear c hroma t in or cvtes with hy po lobu laled or non-lobulatedreport ed maie.temare ra tio var ies , b ut bi zarrely seg me nted nuclei, and abnormal nuclei 1266, 9281. Usually the M:E ratio isbased on the larger series reported , is cytop lasmic granu lar ity m ay be obse rved g reater than 10:1, but in some cases ery·approximately 1:1 1266 ,928 , 1208,1 3961. in the neutrop hils. Mod erate anaemi a is th roid p rec ursors ac count for ove r 30% 01 frequ ent and the red blood cells may show the 8 M ce lls, Dy serythropo iesis is presentSites of involvem ent c hang es indi ca tive of dysery th ropoiesis, in at leas t 50% of c ases 11 89, 266, 9281 _The pe riph eral blood (PB) and bone ma r- inc ludi ng macrcovaiocvtosrs. The platelet Inc rea sed reticu lin fibres are seen in somerow (BM) are alwa ys invol ved: sp lenic and cou nt is variab le, b ut thrombocytop enia is c ases at the time of d iagno sis , or mayhep atic invo lvement are also common.Cl inic al featuresThere are only a lew reports of the clinicalfeatu res of pa tien ts with aC ML. Most pa-tients have symptoms related 1 anaemia or 0some times 1 thrombocytopenia. whereas in 0others the chief complaint is rela ted tospleromega" 1266. 928 .1206. 1396.20031.Mor phology and cytochemistryThe white blood cell (WBC) count isalways ~ 13x 1r1fL 11891 but median valuesra ng ing from 24-96x1Ql1L have beenreported and some patients have WBC80 MyekldysplasticJrnyeloproliferative neoplasms
  • 77. Fog. .07 A - ». ...... -, ~ typical chrOIlIt myeloid leukaemia. A Bone ITlIITOIfIbiopsy shows 1Iypetc:eIIWnty. 0Je to~ proMerabon B NcJ(e anncrease " Ihe l1JITtler of rnegak.afyocytes,... smal abnonnallorms From the biopsy alone. !he fTOlIhology wWd be dlfliQjt to tjfterentlale from BCR-ABl. po5IbYe chronic myelogenous leukaenia C Bone marrow. . smear. Oysplasia in !he ~ and the megakaryo:;ybC lineages is eWlenI.appear later in the course of the disease. Genetics Postulated cell of originMost cases reported as the syndrome of Karyotypic abnormalities are reported in Bone ma rrow haematopoietic stem cell.a~mal chromatin clumping " can be up to 80% 01 patients with aCML. The mostconsiderec:l as a ....ariant of aCML 1276. 680, CCfTITlOlI abnormalities are +8and del(2Oq) , Prognosis and predi ctive factors10071. These are characterized in the P8 but abnor malities of chromosomes 13, 14, Patients with aCML fare poorly, The series.nt 8 M by a high percentage 01 reuno- 17,19 and 12 are corrvnonly repor ted as reported to the present time include only:tits and precursors that exhibit exagger· Nell 1266, 928.13961. Rarely, patients whose small numbers of patients, but medianeeock.mping of the nuclear chromatin . neoplastic c ells have an iso lated isochro- survival times range from 14 -29 months«> specific cytochemical abnormality has mosome 17q may have features of aC ML 1266, 928, 1208 , 20031. Age >65 years ,been reported 10 date, although stains to although most will fulfill the cr iter ia for female sex. W8C >50x 1Q91l thrombo-detect a significant rnoncx:ytic component CMML 11437f. cytopenia, and Hb <10g1dL have beencan be use ful to exclude chronic myelo- There is no BCR·ABL 1 fusion gene. repo rted to be adverse prognostic find-monocytic leukaemia (C MML) . A non- Cases with rearran gement of PDGFRA or ings {266. 9281. Howeve r, pa tients whoSPecific este rase react ion performed on PQGFRB gen es are also specifica lly rec eive 8M nansptantanon may have ana BM asp irate may identify sign ific antly excl ude d. The ac tiva ting JAK2 V617F improved outcome 111781. In approximatelymore monocytes than are ap prec ia ted by mutation has been reported in some c ases 15- 40% of patients, aCM L evolves toroutine stains. l e ukoc yte alka line phos- of aCML {1064, 12871. Approx imately 30% acute mye loid leukaemi a. wherea s thephatase scores may be low, normal o r of cases are ass ociated with acquired remain de r die of marrow fail ure {266.elevated. and thus are not useful for mutat ions of NRASor KRAS1 2311 1, 12081,diagnosis 11208. 13961 . Some c ases of t(8; 9)(p22;p 24 ) with the PCM1..JAK2 fusio n gene have bee nImmunophenotype reported as "aCML" 1259, 18331 but d ataNo speci fic imm unop henotypic c harac- cu rrently ava ilable suggest they hav eteristics have be en reported to date, A s eosinophilia and lack mye lody sp lasia andwith cytoc hemistry, immunohistochemical may be better regarded as chronic eosino-studies for CD 14 o r CD68R on biopsy ph ilic leukaemia. Meticulous description ofsections may he lp to id entify monocytes: the morpholog y of atypical mye loid prout-fnding a significant 8M monocytosis era tions associated with var ious geneti csllould call the di agn osis of aCML into defects will be necessary to assign themcoesnon. to appropriate ca teg orie s, AtypIcal crvooc myeloid leukaemia. BCR-ABL 1 reqanve 81
  • 78. Juvenile myelomonocytic leukaemia I Ba umann J ,M. Benn ett C.M. Niem ey er J , Thiele K , ShannonDefinition Etiology - •Juvenilemyel:m:>nocyt<; ""-<aemia (JMMLIis a clonal haematoocietrc disorder ofchildhood characterized by proliferationp rinci pally of the gr anulocytic and m0no-cytic lineages. Blasts pius promonocytes The c ause of J MML is not known . Rare c ases have b een repo rted in identical twins 17051. The association between NF 1 and JMML has long been established 1345. 1595 , 2 1011. In contrast to adults who •• . • • • .~ • 1account for <20% of cells in peripheral hav e NFl . children with NFl are reported <)blood (PB) and bone marrow (8 M). Ery-throid and megakaryocytic abnomaunes to have a 2OQ. to 5(X).fold increased risk of developing myeloid malignancy, mainly •are frequently present 132. 303, 14771. J MML 115951.Occasionally young infantsBCR·A8L , is absent, whereas rrctato-s in-volving genes althe RASIMAPK pathway with Noonan syndrome develop a JMML-like disorder, which resolves without treatment • FIg.4.111 ..hJyrie myek:m:lnocytlc IUaeITia I.MUare cha rac teristic . in some cases and behaves more aggres- PenpheraI blood smeal" shoWn;l abnornIaI ~ sively in others 11211 , These children carry wotrl C)t:IpIasmic vacuolesand two oormoblasl5.ICD-Ocode 994613 germhne motanons in PTPN11,lt1e gene encocting the protein tyrosine phosphatase have lymphadenopathy. In addition , W- SHP2121621 or in KRAS 119741 . aemic infiltrates may give rise to markedy enlarged tonsils . Signs of bleeding are Sites of involvement frequent and about a quarter of the caressEpidemiology The PB and BM always show evidence of have skin rashes. Cafe au tait spots areThe inci dence of JMMl is estimated to be myerononccvnc p roliferation. Leukaemic noted in patients with NFl .approximately 1.3 per millio n ch ildren in filtra tion of the liver and spleen is found A remarkable feature of many JMML cases0- 14 years of age per year. It accounts in virtually all cases, Although any tissue is a ma rke dly increased synthesis 01for less than 2-3 % of altleukaemias in may be infilt rated, lymph node, skin an d haemoglobin F, specifically in cases WIthchi ldren, but for 20-30% of all cases 01 t he resp iratory t rac t are other co mmon a normal ka ryotype 1345. 1595 1 AddrtiClrl! .mye lody splasl ic and mye loproliferative sites of invo lvem ent 1345, 134 6 , 15951 . fea tures include polyclonal hyp ergamma-disease in patients < 14 years of age 1907. globulinaemia and the p resenc e of auto-17041 The age at diagnosis ranges from . antibodies 1345, 159 5 1 The cl inical and .one month to early ado lescence, but 75% Clinical features laboratory featu res of JMML sometimesof cases occur in child ren <3 years of age Most patients p resent w ith constitutio na l clos ely mimic infectious diseases, including1345, 1346 , 1595 1, Boys are affec ted nearly sym ptoms o r ev idence of inf ect ion 34 5 , those du e to Epstein-Ba rr virus , cytomega-twic e as freq ue ntly as g irls , Ap proxi- 1346, 1595l . There is generally ma rked loviru s, human herpesviru s 6 and othersmat ely 10 % of cases occur in c hild ren hepatosplenomegaly, Oc casionally sp leen 11 376, 1596, 17511, Ap p ropriate laboraicvwith the c linica l diagnosis of neurofibro- size is no rm a l at di agn osis but rap id ly testing inc luding mo lecu lar stud ies and if1matosis type 1 (NF l) 1345 , 1595,2 10 11. inc reases thereafter, About half the patient s vitro c ultures may be requ ired to exclude infec tions as a c ause for the clinical arc haematoroqc find ing s In vitro, there is ma rked hy persensitivityolTable 4.03 Diagoosticarteria of juveoile myelomonocytic leukaemia" myeloid progeni tor cells to GM -CSF 16441; 1. Feflpheralblood ~ >b lOIL this has become the hallmark of the d isease 2. Blasts (ird.Jdlng ~)" In <:!(l%of lie leUor.ocyles II eeblood 1Rl of !hermeated beneITI8ITtlW eels and represents an important diagnostic lo:t 3 No Ph dlomosome or BCR-ABL1 fusion gene Morphology and cytochemistry .4 Plus two ex more dille loIowing: The PB is the most important specimen III - HaemogIoI:lln F irocrea&ed lor age proving the d iagnosis. It gener ally stoes - IrmIature granulocyles in the peripheral blood - WBC counl >10J;10"/l leukocytosis, throm bocytopenia and oae- anaemia 1345.1346. 15951. The median re- • Clonal d1I01TC1SOm111 abrlormIldy (may be monosomy 7) ported .....tIile blood count (NBC) varies lrcm • GM.csF hyper5enIIbviI of myeIold progerIIIor5 on Iitro 25-30x1Ql1Il, but rarely is >l00xll1i. The leukocytosis is comprise d mainly aI "McOfled from 11596}. neutroohns. with some immature ceus ."In IIliScialslkalJon. protII(lllCICy In equivaIer( 10 bIa5ts. such as promyelocytes and mveocytes.82 Myelodysplastic/myeloproliferative neoplasms
  • 79. as well as of roonoc ytes . Blasts (includ ingpromonocytes) usuall y account for fewerthan 5% of the white cells, and always lessthan 20%. Eosinophilia and basophilia areooseved in a minority of cases, Nucleatedred blood cells are often seen . Red bloodcell changes include macrocytosis, partie-ularty in patients with monosomy 7, but nor-mcx:ytic red cells are more common, andrecrocv tosrs due to iron deficiency or ac-QOired thalassaemia phenotype 1961} may Fig. • t Juvenile myeIomooocytlc leukaemia, A The bone marrow- aspole &IM3f usuaty refIecls thedafIge$ noted Ube seen as well Although platelet counts in the blood. buI !he monocyle ~ lllIlI is dmft10 appreciate, 8 ACOlTiwoed alpha naplhyI acela1e eslefase andare variable , thrombocytopenia is usual and naptl~ esterase eaclion idenblies the vanulocytlt (blue reaction product) and the ITIOflOCYlICmay be severe 1345, 1346, 1595, 17051. component (brown feacbon product . A lew eels contain bolh pnxIuct$ )Bone mar row f indings are not by them-selves diagnost ic . The 8M aspi rate andbiopsy are hyperce Uular with grallUloCytic •proliferation , although in some patientserythfoid p recursors may p redominate1595, 17051. Monoc:ytes in the BM areoften less impressive than in the PB .generally accounting lor 5-10% 01 the BM cells. Blasts (including prorooo-cytesj account tor <20% 01 the 8 M cells. and Auer rod s are neve r seen . Mos t often dysplasia is minimal. However, dysgranu- Fig. 4.10 Juvenile ~ lOCytJc leukaemia, A The b<:Jre marrow is ~ wrlh g~pn:lilefabon. ccorese. including pseudO Pelqer-Heet B The megakalyocytes are reduced in IlUfTlbef, but appear rTlOIphologlcally IlOffIIII in Ihe biopsy Blasts are not neutrophils or hyp:>granularlty may be noIed substantially ineteased in rvnber. foC~ n some c ases and eryt hroid precursors may be enlarged, Meg akaryoc ytes are cnen reduced in number, but marked rregakaryoc ytic dysplasia is unusual 1 345, 1595, 17051 . Reticulin fibrosis has been noted in some patients 13451 . Leukaemic infiltrates are common in the skin where myelomonocyt ic ce lts infiltrate the superfic ial and d eep der mis , In the IU leukaemic cells spread from the cap- l"Ig, illaries of the alveo lar septa into alveola e . ¥ld il"l the spleen they infiltrate the red pulp , and have a predilect ion for trab ecular and central arteries , In the liver, the sinu soidseoo the portal tract s are infiltrated , ~ specific cvtocterracai abnormalities have been repor te d in JMML. In 8M as pirate smears. c ytoc hem ical sta ins for alpha naphthyl acet ate esterase Of butyrate esterase, alone o r in combin ation wi th naphthol-ASD-chloroacetate esterase, may be helpf ul in detection of the mono- * Fig. 4.11 JU.OOile rnyeIofnoncq1ic leukaemia. The leukae ~ infiltrate in the Iivef isin the portalregiOns (AI as wei as cytic compone nt . A lthou g h leu kocyte in !he hepa sinusoids (8) , C The leukaemicI1filtrale in !he red pulp of !he spleen encroadles ~ !he gemiIIaI ten. lic all.aline phos p hatase scores are reported Int. 0 The infiltJale is compfised mainly of immalufltand maluflt neutrophils and fTIOflOCYes. to be elevated in about 50% 01 patients,- type this test is not helpful in establishing the diagnosis 113461 . is best detected by irTVTlunohistochemica l Gene tics techni ques that detect lysozyme and Karyotyping studies show monosomy 7 in CD68 R. However, individual cases may about 25% of patients, other abnormali- " speo!ic ~abroonaJ" show almost excluswetv infiltration by ties in 10%. and a normal karyotype in rave been reported in JMML. In extra- myeloperox idase-positive granulopoietic 65% 115951. Philadephia chromosorneand ~ 1JSSUeS, the monocytic COflXIl8llI precursor ce lls . the BCR-ABL I fusion gene are absent. JlIVenile myebnonocytic leukaemia 83
  • 80. There is evidence that JMML is, at least inpart. due to aberrant signal transduction GM~SF R a s -GDPresulting from mutations of components of G, b2 SO~ ~ ---.......r-, I the AAS/MAPK signaling path way, So-matic mutations in PTPN 11 occur in 35% She Ga b2! ~ .-INeurofibforrinof patients 11329, 21621. and oncogenic SHP-2 - - "..,"""""~mutation of the RA$ genes, NRAS andKRAS2, and of NFl are each seen in ap- GM~SFRpro ximately 20% 121621. Mutations in PTPNU Mutation (-35%)PTPN1 , the RAS genes and NFl arelargely mutually exclusive, suggestingthat pathOlogical activation of AAS de-pendent pathways plays a central role inthe pathophysiology of the disease. I EttK tor Path waysIn JMML cells of children with NF 1, unr-parenteral dlsomy results in dUplication ofthe mutant NFJ allele 1714, 20961 . Sincethe NFt gene product, neurouoromo. is a Fig.4.12 Molecular lesions ~ Ras sir¥*!l prOWlS in JMM.. GM-CSf normaIy binds kI its rec:epD". in1alnegative rroourato- 01 AAS function, the IIeterIXlin1er ¥d asserrbIes 8 ~. d S9*9 mclIo.JIes ald adaplets flat ile1.I::les She: and GttI. ThesIloss of the normal NFt allele is associated proieln$. " un. ftICI"Uit Gab2 SHP-2 and 505. 1IltliCh eataIyzeI ~ IWJd80lIde ~ lllI Ras and iwnases .with AAS hyperactivity 119971, irr.IoeI.D"leYeIs d Ras-GTP. oee a aetvaaed, Ras-GTP ~ ..... rurtJerd ~ elfectIrs, The Gw. lIdMIlog proB1s pt2OGN and net.6OIibn:mn brld kIRas-GTP and aoc:eIerate lXlfIoeIWn d Ras-GTP kI Ras-W ~ kI GM-CSf is a ceIlW haImart. d JtAt. ltIal resulls from a rurtJer d lisln::l genetic ~Postulated cell of orig in t.lJtaIioI1s in PTPNfl increaseSHP·2 phosphatase acIYlty alderNIce Ras SigrlafrIg. SiTI1arIy. cancer-associaled . . .Haematopoietic stem cell. acid Slbsl.iluIiCII in NRAS or KRAS2 red in /TJJlarIl: Ras prol8in:s IIaIlICO.Il1Jiate " ee acINe. GTP-b:u1d c:onbma- lion. FnaIy. inacIivaIiorI ofllle NF l ~ ~gene ~ Rassigoahng ItlrtXJgh loss ofneurofibormPrognosi s and pred ictive factorsAlthough JMMl rarely trans forms intoacute leukaemia. it is a rapidly fatal diso r-der for most children If lelt untreated . The die from organ failure. such as respiratory effect plays an impo rtant role, since amedian survival time Without allogeneic failure. due to leukaemic infiltration . substantial proportion of children can bestem cell transplantation (HSCT) is about Haernatc poietic stem cell transplant cured alter a failed HSCT by donor 1ym-one year. Low platelet co unt, age above 2 (HSCT) from a related or unrelated HLA phocvte infusion and immunomodulatoryyears at diagnosis and high haemoglobin F com patible donor c an cu re about half the therapy 117871. The role of anti-leukaemicat diag nosis are the main pred ic tors of patients 113261. Relapse is the major eeaov prior to HSCT is currentlyu-cetenshort survival 1345. 1595. 17051 In the ab- . ca use of treatment failure, There is clea rsence of effective treatment, most children evid ence that graft versus leukaemia • s ( 1 s ti C T o • 284 MyelOdysplasticJmyeloprolilerative neoplasms
  • 81. Myelodysplastic/myeloproliferative JW. Vardiman J.M . Bennettneoplasm, unclassifiable B.J, Bam I. Baumann J , Thiele A. OraztDefinitionMyelodysplastic/myeloprohferative neo- The case has dirucaI, laboratory and ~ IN!ufes rJ onerJ !he ca1egories rJ MDS (reifacklrypIasm. lIlClassifiabie. (MDWPN. U) meets ~ WIItl unineage: dysplaSIa, relraalryaJla&mia WIIlIIIgSiCIerObIasIs. reIracIory tyqlenia MIhIlUb-!he criteria lor the MDSIMPN category in Iileage ~. relradory anaemia -.ilh elC8SS 01 blasts) and <20"4 blasts in the blood and bone marrowlhat, at the time of irntial presentation ,eee are clinical, laboralOfy and rrcepro-bgicaI features that overlap both MOO and "" Has proITWlenI mye!oploilelalMlleatLres, e.g. pIMeleIaut a 45OJ;10lt associaIed -.ilh megakaryotytlc proIileration, or WBC COld~ 1 h1 l1lt , MIh or WI1hOul PtJn*Ienl spIeIlllfTIllgaIyMPN. Cases classified as MDS/MPN, U00 not meet the criteria lor chronic no "" tia$ preceding tGlfy rJ In ~ WN or rJ KlS , no hlst:lryrJ n!CeflI L)k*JXlC or ~ Iadormyelomooocytic leukaemia . juvenile helapy ~ ccokl e.(j)lain !he ~ or 1ll)eIopi00000llti.. feaUes , IIfId no Fhiadelphiamyelomonocytic leukaemia or atyp ical chCflCSOlII8« BCR-ABL1 k.tsion 98"8, no realral9lll,.ltrJ PDGFRA. PDGFRB or FGFRf,1IfId nodrlnc myeloid leukaemia The finding 01 a isolated del(5q},l(3:3)(Q2I;(l26) or1fIl(3)(Q21q26)oc:R-ABL , fusion gene or of rearrangement11 PDGFRA, POGFRB or FGFR excludes The palienlhas de rICM) disease WItl nned myeIoprolilnlrt8 and myelodyspIastIc features IIfId eatnlttie diagnosis of MDSlMPN , U . be assigned to i1It/ olhercategory rJMOS, MPN«rJMDSIMPN.It is important that the designationUDSnvtPN, U not be used for patients withaprevious, well-defined MPN who develop Morphology and cytochemistry GeneticsOysplastic featu res in ass oc iat ion with These disorders are charac terized by pro- There is nocvtooeoetc or rooIecular geneticeansormeton 10 a more aggressive liferation of one or more myeloid lineages finding specific tor this group. A Philadelphiarrase. HoNever, MD5MPN, U may inc lude that is ineffec tive, dysp lastic or both and c hromo some and BCR-ABL 1fusion genesere patients in whom the c hronic phase simultaneously, by effective pro liferation . should atways be excluded prior to making01 an MPN was not previously detected. with or without dysplas ia, in one or more the diagnosis of MDSlM PN, U. Cases with:rld who initially present in Iransformalion of the other mye loid lineages, l aboratory rearrangeme nts of POGFRA, PDGFRB orMIh myelodysplasticfeatures. If the under- features usually include anaemia of variable FGFRI or w ith iso lated de l(5q) or 1 :3)(3 ~ MPN c annot be identified . the desig- severity, w ith or without mac rocytosis and (q2 1:q26) or inv(3Xq21q26) are excludedration of MDS/MPN , U is appropriate. If ofte n d imor ph ic red blood c ells o n the from th is category as well. In diff icultthere has bee n any rece nt cytotoxic or per ip heral smea r. In addition, there is evi- cases . the p resence of a JAK2 V617F arowth fact or therapy, follow-up clinical dence of effec tive proliferation in one or mu tation may help to confirm a haemato-and laboratory observations are esse ntia l more lineages, e ither as thrombocytosis poietic neoplasm. thoug h the significancekl demonstrate that the peripheral b lood (platelet count ~ 45Ox1Q91l) or leukocytos is of such mutations in this entity is unce rtain.(PS) and bone marrow (BM) c hanges are (w hite b lood c ell c ount ~ 1 3 x 1 09/l ) , Neu- Occasional cases w ith isolated del(5q)lOt due to the treatm ent. troph ils may show dysplastic features and and JAK2 V6 17F mutation have been re- the re may be g iant or hypog ran ular po rted to have features that overlap MDSICD-O code 9975/3 pl ate lets, Blasts ac count for <20% of the and MPN 110051. leukocytes in the PB and of the nucleatedSynonyms cells of the BM , and a find ing of > 10% Postu lated cell of originlIX myeloc routerawe/myelocysptastc ed bl asts in the PB or BM likely indicates Haematccoretrc stem cell.syndrome , unctasstnebre : "overlap" syn- tranetoenetoo to a more agg ressive staqe.acme, unclassilia ble . The 8M bio psy specimen is hypercellular and may show proliferation in any or all of Refractory anaemia with ring sideroblasts&las of involvement the myeloid lineages. However, dysplastic (RARS) associated with marked The BM and PB are always involved: featu res are simultaneously present in et throm bocytosisspleen, liver and other extramedullary least one ce ll line .:ISSUeS may be involved. Cytochem ica l find ing s may be similar to Definition lhose seen in MDS or in MPN, In the third editionof the INHO Ciasetcaton~icaI featu res RAR$- T, previously also referred 10 asThe c linical features of MDSlMPN , U IrrmJnophenotype essentia l thrombocythaemia (ET) with ringOYerlap those found in d iseases of the May be similar to findings in MDS and/or sioerobiasts . was proposed as a provi-l.tOS and MPN categories 1129. 1588. MPN . siona l entity to encompass pat ients who23111 . have the cuncat and morphological fea- tures of the myelodysplastic syndrome, MyelodysplasticJmyeloproliferative neoplasm, uoclassifiable 85
  • 82. AARS, bu l who also have marked throm-bocytosis assoc iated with abnormalmegakaryocytes similar to those observedin the BCR-ABL 1 nega tive MPN, such asET or eartv-staqe primary myelofibrosis(PMF) 1865,1077,21091. However, someinvestigators have suggested that MAS- Tis not a unique entity but instead rep re-sents cases of other subtypes of MDS orwell-defined MPN that have acquired ringsidercbtasts as a secondary form ofdysplasia 119661. It is not clear whetherAAAS-T is a distinct entity, one end of thespectrum of AAAS . a progression ofAAAS due to an addrtiooat acquiredgenetic abnormality. or less likely. Iheoccurrence of two rare diseases in thesame patient. Therefore . until these ques-tions are more ctearly answered . AAAS-Tremains a provisional entityIn support of a myeloproliferative compo-nent to this neoplasm, the majority ofcases reooeted as RAAS- T have shownthe JAK2 V617F mutation, or much lesscommonly. the MPL W515KIL mutation1234. 354 , 762, 1835. 1839. 1969. 2081 ,2 139. 2358 1_ On the other hand. the few ..reported cases with this mutation thathave been studied for endogenous colonyform ation in vitro have demonstrated apattern mo re akin to that of MDS 1 234.18351 . Thus it may be that the provisional Fig. .13 Refractory eneema WIth ring SideIOb~s andlhfombocylosis This sequence of rnitrophotogriljtls AtsIr3ltdesign ation of an MDS/MPN accurately blood and bone marrow 01 a 62-year-old man who presenled with severe anaemia anda plateletcount oI85lb:10"lreflects the underlying biology in a sub- A Abnormal red cells and Ihrontlocylosis. B El)lhroid proliferation and abnormal megakaryocylll$ reserrtIing megNy-stantia l pr oportion of the p atients 1762J; ccytes seen in ET. C Mild dyserythropote$is. 0 The majority01 erythroid pIlICllfSOrS were ring sicleroblasts.more stud y is neede d to further ctarify thisdiso rder. of targe atyp ical mega karyocytes similar GeneticsCases with isolated del(SQ),t(3;3)(q21;q26) to those observed in BCR-ABL 1negative The recent discovery that up 1 60% of 0or inv(3)q 2 1q26) are exc lude d from this MPN (See Chapt er 2). pa tients with AARS-T harb our the JAK2ca teg ory, as are cases with a BCR·ABL 1 The minimum plat elet co unt requ ired for V617F mutation (an inc idence similar tofusion gene, In ad dition, if there has been inclusi on has been lowered to 450xl CY/L that found in ET and PMF) or less corn-a prior d iagno sis of an MPN without ring from 600x 109/L for consis tenc y with the mon ly, the M PL W515KjL mutation, notsioerc otasts. or there is evide nce that the d efining criterion for ET, and because only elucidates the reason for the prolifer-ring stoerotsasts might be a consequence severa l studies have demonstrated that ative aspect of AARS-T but also wooldof therapy or represent disease prog res- pa tients with platelet coun ts lower than seem to move it closer to the MPN catego)sion in a patient wi th features tha t meet 6OOxlCY/L may have biological features, 1234, 354. 762. 1835, 1839, 1969,2081,the crite ria of another well-de fined MPN, includ ing JAK2V6 17F mutations, similar 2139, 23581. Thus. studies for JAK2V617F,this designation should not be used. to those with coun ts ~x1Cf1A..1354I . It is and. if ind icated, for the MPL W515M importan t to note that the criteria for mutation should always be performed inIC().() code 9982/3 AAAS-T includes morphologically abnor- such cases . mal meqakarvocytes similar to thoseMorphology observed in ET and in PMF. This criterionThese cases have features of AAAS should aid in distinguishing AAAS-T from(anaemia With no blasts in the PB and those cases of RAAS commonly reporteddysplastic , ineffective erythroid prolif8fation to have a modest increase in their plateletoften with megaloblastoid features, ring count. Nevertheless, we recommend test-sideroorasts :2:- 15 % 01 the erythroid pre- ing for JAK2 V6 17F when the plateletcursors. and <5% blasts in the BM) and count is elevated in patients with AARSthrombocytosis With a platelet count until the borderline between AAAS and:2:- 450x1CJ1Il associated with proliferation AAAS-T is more clearly defined86 MyelodyspiastiC/myelop rollferallVe neoplasms
  • 83. CHAPTER 5 Myelodysplastic SyndromesMyelodysplastic syndromes/neoplasms. overview Refractory cytopenia with unilineage dysptasia Refractory anaemia with ring siderobtastsRefractory cytopenia with multilineage dysplasia Refractory anaemia with excess blastsMyeladysplastic syndrome with lsoleted del(Sq) Myelodysplastic syndrome, unclassifiable Childhood myelodysplastic syndrome
  • 84. Myelodysplastic syndromes/neoplasms, A.D. Brunning A.Orazi APOfWit I. Baumamoverview U. Germing M .M . Le Beau J .W. Vardiman E. Hellstrom-LindbergDefinitionThe mveoovsptasnc syndromes CMOS) - Iare a group of clonal haematopoiencstem cell diseases characterized bycvtopeorats). dysplasia in one or more ofthe major myeloid cell lines. ineffectivebaematopoesis. and increased risk ofdevelopment 01 acute myeloid leukaemia(A ML) 1190. 353, 23101. There is an en-hanced degree of eoootosrs which con-tributes to the cytopenias 12601. The :. .It • Fig. 5.01 Bone mamJIIIII smear from a palel1t Mlh Fig.5 .02 Bone marrow smear from a . 1.year-d:lthresholds for cytopenias as recom- ~s B19 irltedlon showing mal1<.ed eryttvoid Mlh pancytoperia being cIYooic:aIy poiscWledmended in the International Prognostic hypoplasia wiltI occasional pi eryttYoblasts Mlh lneIic. There is maked ~SCoring System (IPSS) lor risk stratification dispetsed dwomalin and line cyIqllasmic YlICUllIM.in the MDS are haemoglobin < lOgJdL.abso lute reurroptut count (ANC)< 18x l(Jl/l and platelets <l00xl(JlL 1833.833AI. Values above these thresholdsare. however, not exclusionary for a diag-nosis of MDS If delinitive morphologicand/or cytogenetic findings are present123271 The dysplasia may be accompa- .nied by an increase in myeloblasts in thepe ripheral blood (PB) and bone marrow(BM) b ut the numbe r is <20% , wh ic h isthe req uisite thres hold recommended forth e di ag nosis of A ML. It is important 10 Fig. 5.03 Bone marrow smear from a 57-yeaf-okl womanrecognize that the threshold of 20% b lasts ¥r1Io received several dl&molh&rapetJtlC ageots lor breastin the PB or 8M for the d istinction of A ML carcinoma ir.clooing loIic acidantagonists.from MDS does not represent a therapeu-tic mandate for treat ing pat ient s w ith 20%blasts as acu te leukaemia . A treatment Ep ide miology Etiologydec ision 10 manag e the patient as AML or Myetodysplastic syndromes occur princ i- Prima ry or de novo MOS oc cu rs without aMDS mu st be b ased o n seve ra l fa ct or s pally in olde r adu lts with a median age of know n history of c hemotherapy or raceincluding age, prior history of a mveoovs- 70 years . with a non-age corrected annual nonexpos ure. Possible etiolog ies for preplast ic syndrcrne, overall clinical assessment incidenc e of 3-5/100 000 p ersons bu t ma ry MOS Include benzene exposure atand tempo of the proc ess, wh ic h are the rising to >20/ 100 000 amo ng tho se ove r levels well abo ve the m inima allowed bysame determi nant factors for patients w ith the age of 70 years {109, 7831. App roxi- most government age nc ies. cigarette 30% bla sts. Althoug h progr ession to AML mately 10 300 inciden t cases of MOS smoking, exposure to agricultural cherri-is the natural course in many cases of were d iagnosed in 2003 in the USA cats or solvents an d family history ciMoS, the perc entag e of pa tien ts who {1351 1. There is a male predominance . heematoootenc neoplasms 121131. Somep rogr ess varies substantially in the various Thera py-related mveioovsptasuc syn- inherited haematolog ic al d isorders. SUCllsubtypes; a higher percentage of MDS wittl dromes are discussed in Chapter 6. as Fanconi anaemia. dyskeratosis Cl)foincreased myelo bla sts transforms to AML geni ta. Shwachmann-Diamond evnocre178 1.1 3 711 Althoughthemajorityof MOS Cli nic al featu res and Diamond-Brackten syndrome areare c haracterized by prog ressive 8 M Iail- The major ity of patients present with also associated with an increased risk aure. the b iOlogiC course in some patients. symptoms related to cvtooentats): most of MOS.e.q. refrac to ry anaemia with unilineage the patients are anaemic and transfusion-dysplasia (RA) and refrac tory anaemia dependent. less frequent are neutropenia M"",hoIogywit h ring sroerobtests (AA AS). is p ro- and/or thrombocytopenia. Organomegaly The morphological classitication 01 MOOlonged and indolent with a very low inci- is infrequ ently observed. is principally based 00 the percent adenced evokJIi:rI toM1L 1781. 1370. 2327 1. blasts in the 8M and PB. the type an:!88 Myelodysplastic syndromes
  • 85. degree of d ysplasia and the pr esence of nuc lei and det( 17p ) with hypo lobe ted drug history and no case of MOS shouldring sideroblasts {1 90 I. The cy topen ias neutrophil nuclei / 12371 be reclassified while the patient is ongenerally co rrespond to the d ysp lastic Assessment 01 the deg ree of dysp lasia growt h teeter therapy, inclu ding erythro-lineage. but discordance may be present may be pr ob lematic depending on the poietin. In add ition, cytopenia(s) in the(T able 5.0 1) 1 23271 To determi ne the . quality of the smear preparations and the absence of dys pl asia shoul d not beblast perc entage in the BM, a 500-ceU stain. Poor quali ty smears may result in interpreted as an MOS. A presumptivedifferential of all nucleated cells in a smear misinterp retation of the presence or ab- diagnosis of MOS may be made in the ab-ortrephine imprint is recommended and in sence 01 dysplasia particularly in assessing sence of dysplasia il certa in cytogeneticthe PB, a 2QO.leukocyte cnnerentrat In neutrophil granula tion . Because of the abnormalities are present (See Genetics).severely cvtooenrc patients, butfy coat critical importance 01 recognition of dys - Persistent cytopenia without dysplasia andsmears of PB may tacuuare performing the pl asia to the diagnosis of an MOS, the without one of the specific cytogeneticOdferential. necessity 01 high quality slide preparations abnormalities c onsidered as presumptiveThe charac teristic s of the d ysplasia are cannot be overemphasized. Slides for the evidence of MOS should be viewed as therelevant when diSlinguishing between the assessme nt of dysplasia should be made recent ly described "idiopathic cytopeniavarious types 01 MOS and may be impor- from freshly obtained specimens ; speci- of undetermined siqrufcance" ( leUS),tant in predictmg biology. In addition , mens exposed to anticoa gulants for more and the patents haematologic and cyto-some cytogenetic abnormalities are than two hours are unsatisfactory genetic status should be cerefuny moni-associated with characteristic d ysplastic As a general precaution, no patient tared 124221 .features, e.g isolated del(Sq) and hypo- should be diagnosed as having MOS In an attempt to more accurately pred ictlobated and non-lobated megakaryocyte without knowledge 01 the clin ical and chnical behaviour, cases of MOS without "- 8100dMdinp ReIrDIlyq10perIIas IIII1lriineage dysplasia (RCOO) ~ or bicytopenia IJn*Ieage dysplaSIa. 2:10% dille cells Ifl onemyebd i1eage Refraclory anaemia (RA); Relracloryneutropenia (RN); <5%_ - t«I or rareblasts « 1%)1 _ _ IRT) <1510 01 eryIhrOId precursors are nngSlderobIasts Retacklry anaemiI WIth nngsidetobltsts (RARS) 2:15% 01 eryIhroid precursors on rilg SlderobIasts Erylhmid dysplasia only No " <5%blasts Cylopenia(s) Dysplasia iI 2:10% 0I1Ile cells in 2: two myeloid Iille<tges No or fare blasts « 110)2 (neutrophil and/ r erythroid prealrsOfS and/or megallaryocyles) o NoAlIeIrods <510 blasts in marrow <~10"11. monocytes NoAuIM rods 1;1510 ringsideroblasls Refradory anaemia With e~C8SS b1asts--1 (RAEB-1) Cytopenia{s) Unilineage or ml,lttl l~age dysplasia <5%blas ts 5-9% blasts l NoAutlr rod s NoAuerrods < 1 ~1O"fl mooocytes Refractory ana&mia with excess blasts-2 (RAEB·2) Cytope nia(s) Unilineage ormullilineage dysplasia 5-19% blas ts 10-1 9"1o blasls Auerrods t 1 Auer rods 1;1 <1~10J1. mooocytes M)elodjSplastic syndrome - undaSSifJed (MDS-U) Cytopeflias Uoequivocal d~sia in less Il<In 10% 01 eels ill one 5:1% blasts or moremyeloid cell joes v.t1en a<:compaflied by a C)ogene~c abnormallt) considered as presun1pIlve evideflCe fora diagnosjs 01 MDS (see Table 5.(4) <5%blasts """"" UsuaRy JM)n1I3I or Normal 10increased megakaryocytes WJ1h <5% blasts tJwoIobated fIUdei we.ased pIaIeIet COUI1l No_ _ cytogenetic al:inl:lrmlliTy Isolated del{5q) Noor rareblasts «,%) 8qqlenIa may 0CCiI5i0naIy be obseMld cases Wl1lI pancytopenia should be classified as t.I05--U. I . . . JIlaflDW myeloblast perc:entBge is <5% bul1tlEWe ere 2--4% myeIoblasls nee blood, ee liagnosticdass1Iic:aticrl is RAEB 1. Cases 01 RCUO and RCMDIIoilh I %- Il)IlIoblasts IIIlhll blood shoUlIbe dassifled as MOS, U Cases W1111wfII rods nI <5% myetlbIasls III lie blood arw3 0(10% inee I!llll1tIW sInJId be d8s$lIied ... RAEB 2.
  • 86. ,-- - ~ 1 0% dysplastic megaka ryocytes basec on evaluation of at least 30 megakaryo. cvtes in smears or sections, Future snoes may result in modification or this recco- mendation 114201. Mcromeqakaryocves and mullinucleate megakaryocytes are the most reliable dysplastic findings inttl megakaryocyte series 11420. 23271. Although the majority of patients w MDS and unlineage dysplasia pre --"" with a single cytopenia. this revised -.Fig. 5.05 A Blood smear from a paJ8I"It on grarUocyte COOny sbmulating!acttJr. A neutrophil WIIh a bIlobed nucleusand naeased azuror:I* grClruabon. B The same SI)Itinen as (A) showing a myeloblast. etcatoo allows lor bicytopenia in refracby - • cytopenia with lXlilineage dysplasia (00,.q and RARS (Table 5.02). The majority ~ patients with RCMD have 2 cytopeMS 118641. Ch.aracteristics of dysplasia Dyserythropoiesis is manilest prine by alterations in the nucleus ine budding, internuclear bridging , karyCI- rhexis , mu/tinucl€arity and megalobla changes; cytoplasmic features . ring siderobIasls. vacooIisalion and penxk acrd-Sctnf positivity. either diffuse (I granular (Table 5.03). Dysgranu!opoiesl is characterized primarily by nudelJ hypolobation (pseudo Pelqer-Hoetj a~an increase in blasts are recognized as erythroi d cells. In refractory cytopenia hypersegmentation. cytoplasmic hypo-manifesting ei ther unilineage or multilin- with mul lilineage dysplasia (RCMD) with granularity. pseudo Chediak-HigaSJeage dysplasia In RA and RAAS. the or without ring sioe robleete. significant granules and small size. MegakaryocytPdysplasia is generally confined 10the ery- dysplastic features are rec og nized in two dysplasia is characterized by micro-throid lineage. Unilineag e dysplasia may or more of the major myeloid cell lineages. megakaryocytes with hypolobated nuclEi,also occur in the neutrop hns. refrac tory The reco mmended req uisite percentage non-lobated nuclei in megakaryocytes Iineutrop enia (AN), an d megakaryocytes. of cells manifesting dys plasia to qualify as all sizes, and multiple, wrderv-seoaraiearefrac tory thrombocytopenia (AT), but sig nific ant is ~ 10% 11864J in the erythroi d nuclei, Megakaryocytic dysplasia maytltthese processes are much less frequ ent p rec ursors and granulocytes, Significant more readily app recia ted in 8M secncsthan unilineage dysplas ia invo lving the megakary ocyte dysplas ia is defin ed as than smears and both types 01 specimers should be eva luated The cha racteristics of the dysplasia maj be relevan t in pred icti ng biology of aTab le 5.02 Summary of cytopenias anddysplasia characteristics in MOS without an illCfease of marrow blasts. mveicoysorastc d isorder and the relatco- Cytopenia(s) Oysplasla Categories ship to specific cy toge netic abnormalities, ego Sq-syndrome {2327}, Unilineagedys- Unicytopenia Unilineage Refractory cytopel1ia with unilineage ptaaia is o bserved in RCUD and RARS Bicytopenia dysplasia (RCUD) Multilineage dysplasia involving two c. Refractory anaemia (RA) three of the myeloid ce ll lines is rTlOfe Relfactory Ile(Jtropenia (RN ) frequently observed in the high-graClt Relfactory tnrombocylcpenia (RT) p- -- MDS an d is used to distinguish ReM!) -... Biq10penia UflIinelIge and 2:15"" ringSideroblasts Relr<lclory aI1aerTlla with ring SIIiIroblasts (RAAS) from ACUD 118641. Similarly, the presence 01 multilineage dysplasia is used separate RARS from RCMD with n "- - ""","", MyelodysplaslJc syndrome. uocIasS/fled (MD5-U) sroerobtasts. the latte r of which has a Retractory cyIOpenia Wllh mullilneage d:y$plaSiII similar clinical course to RCMD_ increased number of ring sioerotnasa -- (2:2 myeloid eels Ines) (RCMO) occasionally> 15% of the erythroid pre- - "- cursors. may be observed in refract anaemia with excess blasts (RAEB). TIt defining criteria of RAEB- l or RAEB-2 "- dictate the classification in such cases90 Myelodysplastic Syndromes
  • 87. of AAEB-2 o r CM ML-2 in the con tex t of MOS or MOS/MPN rega rdless of the blast perc entag e. This concept is reta ine d in the p resent classification. Cases of MOS with <5% blasts in the 8M and < 1% in the P8 may rarely have Auer rods. These cases have be en reported to be associ- ated with an adverse prognosis 124151 . Differential diagnostk: considerations A majo r problem in the diagnosis 01 MOS Fig. 5.10 Neutn:lphi WIlll a rlOIHlbaledru::Ieus (pseuclo is the determination whether the presence PeIger-HuiIJ in. bbXI smear from a paIienl on ~ 01 myelodysplasia is due to a clonal disor- mol3ZOle. ApproXllTlalely 50 percent 01 the neuIrtlpt* der or is the result of some other factor. had a simiar appearance. The presence 01 dysplasia is not in itsell definitive evidence of a clonal disorder. There are seve ral nutnnoner. toxic and other factors which may cause myelodys- plastic changes, including but not limited to vitamin 8 12 and folic acid deficiency, essential element deficiencies and expo- Fig. s.ar A AtmrmaI bcaizaIon 01 inmaIue~. sure to heavy metals, parncutarts arsenic Bone marrow sectJon lIom I ease 01 RAE&-l and several commonly used drugs and allIlain$ I locus 01 immature myeloid preo.nor$. biologic agents 12601. The antibiotic SAlocus 0I1nmnJrec:eIIs in. bone rnatTOW biopsy from cotreroxezoie may cause marked neu- aesse 01 RAE&-2 reacted wl1t1 I nbbody kI C034. A trophil nuclear hypolobation indistinguish- FIg. 5.11 BtnucIeate mega~ in a bone marrow lIIap:IIIty oIlhe mmature eels are posilMl. able from the changes observed in MOS. smear from a pabeflt with• ~ history 01 refrackIry In some patients on multiple d rugs it may 1hrontlocytopen There is a central !13f1JIOtnere and a The relationship betw een cvtopenras. be d iffic ult to id entify the causative agent peripheral hyalomere. type of dysplasia. and classification is of the neut rophil changes 11136. 2 1411. summarized in Table 5.02 . Congenital r eematoioqcat disorders such striking nuclear hypolobation 11968): blasts The significance of the Auer rod in as conge nital dyseryth ropoietic anae mia may be observed in the PB and may myeloid disorders has histo rically been must also be considered as a cause of reach levels of 9- to% and rarely higher sonewttat uncertain. For severa l d ecades dysp lasia when it is con fined to the ery- in p atients with no evidence of AML or Its detection was viewe d as virtually di ag- throid cells. Parvovi rus B 19 infection may MOS. The 8 M b last perc entag e is gener- nestle of AML. There was no specificity be assoc iated with ervtn robreetopente ally normal, but may be inc reased as well. applied to it with the introduction 01 the wil h gi ant megaloblasl oid eryl hrob lasls: Paroxysmal noct urna l hae moglo binuria concept of MDS by the FA8 gr oup. In the the imm unosu p p ress ion age nt myco- may also present with features similar 10 revised FAB c lassi fica tio n of 1982 it was phe nolate mofetil may also be associated MOS. As a result 01all these possibilities. veweo as evid ence of a high -gr ade MOS. with erythrob lastopenia. Chemotherapeutic it is extremely impor tant to be aware of the refrac tory anaem ia with excess of b lasts age nts may resu lt in mar ked dysp lasia of c linical history including expos ure 1 0 in transformat ion , (RAEB t ), irresp ectiv e al l mye loid ce ll lineag es. Granuloc yte d rug s or c hemica ls and cons ider non- of the blast perce ntage in the PB or 8 M colony- stimu lating fact o r res ult in mo r- clo nal d isorde rs as possible etiologies 11901 In the pri or WHO Class ification of . p holog ic alteratio ns in the neo trophns. when evalua ting cases with myelod yspla- the MDS it was considered as evidence incl udin g m arked hypergranularity and sia, particularly those c ases with no in- crease in b lasts. Repeat ed 8 M biopsies. •• :- including cytogenetic studies, over a pe- riod of severa l months may be necessary in d ifficu lt cases. Histopatho logy The value of the BM biopsy in MOS is well established 116471. It may aid in confirming . -- • a suspected diagnosis by excluding reactive conditions in which ovsnaemato- • poietic changes may also be observed: it ~ A. ..., f.. 5.01 M~a stJc dysery1hropoIeSil. Bone MlIo ~ Inm., ao:Ul JT8B -Mlh fefracUy ~ Fig. 5.09 Dysplasbc megakaryocyeS. Bone nllWlOW as- pirate smear from a 37-year«l male WIIh ~ can also increase the diagnostic accu- racy and helps in refining the IPSS score .. rrUl*leage dysplasia (RCMD) and complex stIotMg megaka-yocyleswithdysplaslic features. 123281. Assessment of 8M cellularity and ~ 8t:n:lnnIIlItle N:tdng del(17p) and del(Sq). strcmal reactions, e.g. fibrosis. B!eadditi:Jrl<W Overvrew- 91
  • 88. cases of MDS with inadequate aspirates, the blast determination requires a aM biopsy and immunohistochemical studies for C034 may prove invaluable. 1l1VTlUnophenotyping Published studies on immunophenotyprg by flow cytometry in MOS have focused CIl several stra tegies, including determrwg the size and immunophenotype of ee blast population and assessing the matu-Fig. $.12 A Bone marrow bI:lpsy from a case of MDS (RAfB) WIth /II)eIOfbosi 5everaI ~ iIIepresenl B Retio.anstain ona marrow bclpsy from a case of MDS wilh myelofibrosis. There is a marked inaease II ration pattern 0I1he myeloid cell popUatolretia.Wl MIres. More specifically. these studies included immunophenotyp ing of CD34+ cells, ap. plication of SCOfing systems, and patternimportant diagnostic features of the early p rec ursor 8M cells in lhe majorIty of recognition strategies uSing muttiCOObiopsy. The 8M in MDS is usually hyper- cases. Antj-C034 can be used to demon- analysis and comparison with norrn;iIcellular ex oormocenutar: the cvtopenras strate pathologic accumulations of blasts reactive PB and 8M.result from the ineffective reenatcooese. both singly and in clusters in aggressive There is generally good correlation be-Histologically, aggressive MDS may be subtypes of myeloid neoplasms 120501. tween the percentage of blasts as cere-characterized by the presence of aggre- With some fixatives, CD34 will also im- mined by morphologic examination iJgates (3-5 cells) ex clusters (>5 cells) of munoreact with megakaryocytes in MOS , fOJtine smearor irrpVltor ~blasts in 8M biopsies usually localized in IrTYTlunohistologicanalysis with anti-C034 preparations and percentage of CD34.the central portion of the 8 M away from may be especially useful in cases 01 MDS cells determined by flow cytometry ( FC~the vascular structures and endosteal with fibrosis or hvpoceuuiar marrows as However. in some cases there may besurfaces 01 the bone trabeculae. These well as therapy-rela ted cases to assess significant discordance due to signilicartare frequently present in RAEB. The blasts b last percentage. In these instances the myelofibrosis and haemodilute samplescan also be identified by immunohisto- p resence 01 fibrosis ()( fany changes in the As a result, Fe percentages 01 CD34+ eelschemistry with an libody to CD34, an anti- 8M may make accurate cbaractenzanon cannot replace differential counts 00gen expressed in p rog enito r cells and of the process very di fficult. smears, However, Fe may be informal1Ye~ abnormal phenotypes of C034+ cells are Hypoplas tic MDS detected: this could be additional evidence rule$tabons 01 ~Table 5.lJ3 Morphologic ma In a minority of the cases of MDS, approx- dysplasia. In addition, an emerging Oyserylhropolesll N....er Noclear budding imately 10%, the 8M is hypocellular. These c ases have been referred to as hypoplastic MOS. This group , which has noinde- f: athological population of CD34 IJ 01 17 cells in low-grade MDS could Sl.I9" gest evolution of the d isease 116221. Int&rTll.lClear bridging pendent prognost ic signific ance per S8, Ma tu rat io n pa tte rns of erythropoie tic Karyorrtlexis may lea d to d iffic ult ies in the d if/eren lial g ranuloc ytic, and monocytic difterentiatcn Mll ~inuclearity d iag nos is w ith aplas tic a naelT)i~ 1 834. in the normal/reac tive 8 M, as well as the Nuclear hyperlobation 1648 1 In add ition, anti-thymocyte g lobulin . immuno phenoty pe of the mature cells in Megaloblastic changes and other therapies used for aplastic PB have been thorough ly desc ribed using Cytoplasmic anaemia have been used with some deg ree fou r-co lor FC. Erythroid abnorm alities as Ring sideroblasts of success in this sub group 1260, 1302, de termined by the pattern of exoressce ~izaliOn 2477, 24781. It is also impo rtant when con- of H-ferritin , CD7 1 and C010S in gly· PeriodiC acid-SChiff positvily sid ering the diagnosis of hypoplastic MDS cophorin A (GPA) posi tive nucleated cells 10 excl ude toxic myelopathy and au to- reportedly ca n pred ic t morphological ery- ~granulopoie. l. imm une di sorders . throid dysplasia with 98% sensitivity [5501, SmaI or oousually largesize A be rran t maturation patterns in granu- Nuclear hypoiobaliOn MDS with myelofibrosis lopoiesis could pred ict morphological (pseudo Peiger-Huet: peIgeroid) Sig nilicant degrees of myelofibrosis are dysplasia and abnormal cytogenetics in IrT9{PJIar hypetSl:lgmentation o bserved in ap proximately 10% o f the ap proximately 90% of cases 112121. ThJs Decreased granules : agrarWrity cases of MO S. These cases have been flow cytorretrv results co rreiate well with .... """ PseucIo QledIak-HtgastH ~arws referred to as MDS w ith fibrosis (12461. morphology and cytogenetics in MDS -- Most of the cases with fibrosis have ex- However, in cases with borderline dys. ~l)ocytopoiIs ls cess of blasts and an aggressive clinical plasia by morphology and no cytogenetic course. Such cases may erroneously be abnormalities. FC results are highly sug- NudNt hypoklbllJon consid ered low-grade MOS if only the gestive for MOS only if there are three IJ ~ (normaI .,..katytq1es in blast count determined from the 8M aspi- more aberrant features in erymropoietc. I.lIWIJl:illI wilh kltdaled nudeI ) rate, which is usually diluted With P8 , is g ranulocytic or monocytic maturation; evaluated. In the fib rotic group, as in other single aberrant features by FC are na92 Myekxtysplaslic syndromes
  • 89. signific ant. .Cases with inconclu sive Postulated cell of origin Tabl. 5.04 ReCl.lning cluumosomal abnormaliti s and e their frequency in re myelod~aslic syndromes atmorphologic an d cytogene tic find ing s Haematoooetic stem cell. diagoosis.and three or mo re aberrant fea tures byflow cytometry should be reeva luatedover seve ral mon ths for definitive rrorpro- Prognosis and predictive factors The morphological subtypes of MDS can A_" MO ,-110,logic or cytogenetic evidence of MOS, be generally categorized into three risk groups based on duration of survival and """""""" S 0%Genetics incidence of evolution to AM L. The Iow-risk ·1 or del(7Q) -5 or del(Sq) 0% . .. 0% "" "" .r , - Cytogenetic and molecular studies have groups are RCUD and RARS. The inter-a major role in the evaluation of patients mediate-risk groups are RC MD with or S%with MOS in regard to prognosis, deter- without ring srderobrasts and RAEB-1 , Pa- ~ 17Q)or l(17p) . S% -, "mnaton of clonality {833, 16411, and the tients with RAE&-2 constitute the high-risk .13 or del(13Q)ecognltion of cytogenetic , morphologic ,m clinical cor relates . Clonal cytogenetic group. It shou ld be noted that patient s with bcvtopema in RCUO and RARS have del(11Q) del(12p)Of 1(12p) " " .2% -abnormalities are observed in - 50% of been reported to have a shorter surviva l dc(X)(Q13) .2%I,()S cases. Myekxtysptastic syndromes tha n patients with one cyt openia 123271 .associated with an isol ated del(5q) occur Pat ients with one cyt openia in the con textorinarity in women, are c ha racterized bymegakaryocy1es with roo-ocetec Of hypo- of RCMD had a longer survival than pa- tients with two cvtocenra s 123271· 1( 11;16)(q23,p13.3) 1(32 1)(q262;q22.1) 1(1;3)(p36.3:~1.2) ... " 2% .klbated nuclei, refractory macrocytic The importance of c ytog enetic studies as 1(2;1l)(p21:Q231anaemia, normal or increased platelet a prognostic indic ator in MDS has been ~3)(q21 q26.2)Cl:lOO t, and a favourable clinic al c ou rse, recogniZed and c od ified by the Interna- 1(6:9)(p23;q34)and are recccneec as a scecinc type of tional My ekxtysplaslic Synd rome Work ingMDS in this c lassification , The oc c urrence Group 18331 Three major risk categ ories ·(j 17p loss is assoc iated wi th MOS or of cytogene tic findi ng s have been d e- , The ceseece of these at:JnormaIIies as the sc*lAML with pseudo Pelger-Hu6t anomaly. fined : i) good risk -normal karyotype, ~ abrmnaiIy 11 !he absence of rrupho-small vacuol ated neutroohlrs. TP53 muta- isolated del(5q), isolated del (2Oq) and -Y; logic aTlenais no! considered deMiIive evidence lortion and unfavourable c linical course: it is ii) poor risk ---com plex abnorma lities, l.e., 1.40S, In !he seltlng of persistent eytapenias ol ~ origin. lhe olller abnormahties shoWn rest common in therapy-related MOS 2:3 a bnormalities, or abnormalities of (12371· Complex karyotypes (2:3 abnor- ch romosome 7; and iii) intermediate risk are IXIO~ ~ve evidence 01 MDS in the absenc:e 01 defuitive ITlCfPlIOIC9C features. malities) typically include chromosomes 5 - all other abnormalities. andf f 7 [-S/del(5q), -7/del(7q )), and are O A scoring system for predicting survival generally assoc iated with an unfavourable and evolution to A ML based on percent severe degree of cytopenia. clinical course . Several olher cytogenetic 8 M blasts. type of cy togenetic abnormal- Constderatoo of age improves predict abil- lindings ap pear to be assoc iated with ities , and degree and number of cytcoe- ityof survival ; patients young er than 60 characteristic morp hologic abnormalities ntas has been pro posed by this g roup years of age have impro ved survival in the such as isolated del(20q) w ith involve - (Table 5.05) 1833, 833A I, Four risk g roups ind ividual risk ca tegories compa red with ment of eryt hroid ce lls and meg akaryo- based on this sc oring system are recog - patients older than 60 years. cvies. and abnormalities of c hromosome nized : low, O INT (inte rme diate) - 1, The cytoge netic subg rouping of the IPSS 3 (ir (3)(q2 1q 26 ,2) or t( 3 ~ 3)( q 21 :q26,2 )]. w 0 ,5- 1.0; INT-2, 1,5- 2.0; and high , 2:2 ,5. In system also has an independ ent value in which are associated with MOS and AML general, the higher-risk groups are related pred ict ing the outco me of allog eneic stem withincreased abno rma l meg akaryoc ytes to higher 8 M bl ast percent ag e, mo re un- cell transplantation in pati ents w ith MOS 1 866, 1207j. 289, favou rab le c ytogenetic find ings and mo re 15321. Some clonal cytogene tic abnor mal ities oc curing in MOS are not definitive evi- dence for this disorde r in the absence of Table 5.05 Int rnational Prognostic SC:or11g System(IPSSllor MDS (833,833Af. See Prognosis and ptedidive faclQrs e lor interpr tation, e morpholog ic al crtterte. e.q . -Y, +8 or ool(2Oq) as the sale abnormali ty, The ,,~ • ••• , ,.s 2 other abnormalities listed in Tab le 504 in Prognostic variablesee presence of a refractory c ytope nia , <5. 5-1 0% 11 - 19"110 20-30% but no morphologic evidence of dysplasia, " bone marrow blasts are considered presumptive ev idence for MOS. It is recommended tha i tnese pa- Karyotype" C~s - .-, Good Intermediate 2-3 Poot llefllS be followed caretcuv lor emerging "This ~ is ~ as AML in the wtK) classificabon. roorphologi c al evidence of MOS. FISH - Karyotype: Good" normal, -Y,del(5Q). del(2Oq). tJOVides increased senSitivity in monitoring Poor " ~l ~ lIbnormaIiIies) or ....~mlTlOSOl""m18 7...::ma1ies: ~ .. Sl.Ch pateots.once a recurring abnormality Intermecliate " otherIIbnormaIrt.oes res been identified , - Cylopenias: Hgb<1llgk1. NeutropIiIs <1.8xlll11. PIaWets <1 00x 1 ~ i Overview 93
  • 90. Refractory cytopenia with A.D. Brunning A.P. Hasserjian A. Orazr J. Thieleunilineage dysplasia A . Porwit J.M. Bennett E. Heustrorn -LtndberqDefinition dys plasia, although discordance between two successive evaluations should beRefractory cytopenia with unilineage dys- type of cytopenia and cell lineage dyspla- placed in the category of MOS-U becauseplasia (RCUD) is intended to encompass sia may be observed 123271. Some of the of the uncertain biology of this constellationthose myelodysplastic syndromes (MDS) cases previously classified as M05-U may of findings. Patients with 2-4% blasts 11"1which present with a refractory cytopenia be included in this category. e.q. RN, RT the PB and <5% blasts in the 8M shouldwith unilineage dysplasia and includes All non-clonal causes tor the dysplasia be classified as refractory anaemia Withrefractory anaemia (RA) , refractory neutro- must be explored and excluded before excess btasts-t (RAEB-1) if other cnterepenia (RN) and refractory thrombocyto- the diagnosis of MOS is established lor MOS are present. The number dpenia (AT) . Although refractory anaemia These inc lude, but are not limited to, drug cases with these findings is very low anawith ring sioercoiasts is also characterized and toxin exposure, growth factor therapy. these patients stoJd be careftAly coseoecby unilineage dysplasia. it is considered viral infections, immunologic crsorcers. for increasing 8M blast percentage 111651,as a distinct entity of its own . Refractory congenital disorders, vitam in deficiencies Refractory cytopenia with unilineagebicytopenia may be inCluded in the AGUD and possible essential element deficien- dysplasia should not be equaled wiVlcategory il accompanied by unilineage cies, such as copper deficiency 18371_ "Id iopa thic cytopenia of undetermineddysplasia. It is recomnet ICIed that refractory Excessive zinc supplementation has also signiftcance" (ICUS) which lac ks thepancytopenia with unilineagEl dysplasia be been reported to be associated with se- minimal morphologic or genetic criteriaplaced in the category 01 rnyelodysplastic vere cytopenia and dysplastic changes requisi te tor a diagnosis 01 MOS andsynd rome. unctassrnaore (MDS·U). The 110 10 1 It a clonal cytogenetic abnormality . should not be considered as such [24221 .recommended level lor dysplasia is ~ 1 0% is not present, there should be a period ofin the cell lineag e affected. The recom- observation of six months from initial Synonymmen ded levels for defining cytopenias are examination before a diagnosis of MOS is Refractory anaemia.haemoglobin <10g/dL. absolute neutro- established unless more definitive morpro-phil count (ANG) < 1.8x1Ql1IL and platelet logic or genetic evidence eme rges during Epidemiologycount <100x1(19/l1833, 833AJ. However, the observation per iod . Refractory cytopenia with unilineagevalues above these levels do not exclude The presence of pe ripheral blood (PB) dysplasia comprises 10-20% of all casesMDS if definitive morphologic and/or cyto- blasts esse ntially excludes a diagnosis of of MOS 1782, 1371/. It is primarily a ds-ge netic ev idence of MOS is p resent. The RCUD although in an occasional case a ease of older adults; the median age istyp e of c ytopenia in the majo rity of cases rare blast may be id entifie d: pa tients w ith around 65-70 yea rs There is no signifi·w ill cor respon d to the type of unilineage the find ings of RCUO and 1% blasts in the cant sex pred ilection , The vast majorityo!dy spl asia , e.q. anaemia and eryth roid PB and <5% in the bone ma rrow (BM) on RCUD c ases are RA. Refractor y neutro- pen ia and refr actory thrombocyt openia are rare an d extreme c aution should be used in making either of these d iagnoses. Sites of involvement The P8 and 8 M are the p rinci pal sites 01 involvement, Clinical feature s In RCUO. the presenting symptoms are related to the type of cytopenia, The cyto- per n are refracto ry to haernauruc ther- as apy, but may be respo nsive 10 growth factors 19831. Mo<phology Refractory anaemia oco-o code 998013) In the PB in RA, the red blood cells are usually normochrcmic, normocytic or nor-Fig. 5.13 Refradory WIlIeITIia, This bone IIWTt7W smear speomen shows dyspIasbc Jeatures criy in !he8f)1tVOld moctYomic, macrocytic. Unusually, there ispreo.nors; octaSiOnaI erythrobIasl$ sIlClW vacu:lIat8d c:ytopIasm Mel ~ megakXVst*! 1oldBi. anisochromasia or dimorphism with a94 Myelodysplastic syndromes
  • 91. _ AS Fif!. 5.14 A Refraclory neuuopellIa Bklod smear m a 56-year-old male;!tiellIllAJq)hI in lhe bwer IeflIS normal aweamg with weI-grarIJIated cytJpIa$ITI and a namaIy M!1I**I rv- 1IJdIus. The A8IA"ophI inltle l4lP8l is dysplastic wiIh ~ ~ cyq:.Ia$mWld oc:casionaI 0CHe bode&. The I1.JdM; shows retarded MglIl8lI!alJOll. ApprounaleIy IlIIf01 fie nMropIIis III8l1l dyspIaslic. Cytogenetic S!I..des showed .. extra toPI d cnomosome 8 lWld perlOlftlc rNer1ion d ctvornosare 12. B A tIyspIastic megakaI)uyte in a ~ ItTl8al from a ll-year-okl male WIlIl a two year hISlory oIrelradory II1rtlmbocyk:Jp Theie is ~ Ikdearcylopiastllc dewelopll.,1 /IIllh a ~ ~ and 8 norHobated mnaltn nucleus. CytIgeoelic slldIes I this !line stoNed a missing Y chromosome. There was SlbsequenC evokIIIon at which lime ~ -.oes shcMoed a rrWsSlIlg Y, addltIonaI9 and deletion 13. population of hypochromic red blood cells. Neutropenia secondary to drug therapy, Genetic s Anisoc ytosis an d po ikilocytosis va ry from toxic exposu re, infectious processes , im- Cytogenetic abnormalities may be ob- none 10 marked. Bla sts are rarely seen and, mune mechani sms, or other causative fac- served in up to 50% of ca ses of refractory if present, acc ount for <1% of the while tors must be exclud ed , The other myeloid anaemia 1782J Several difterent acquired blood cells. The nectrocnns and p latele ts cell lines do not show signific ant dysplasia clonal chromosomal abnormalities may are usually normal in number and rrorpno- «10%). be observed. and although useful for logy. How ever, some degree 01 either establishing a diagnosis of RA, they are neutropenia or thrombocytopenia may be Refractory thrombocytopenia not specific. The abnormalities generally present (ICD-O code 9992iJ) associated with RA include del(2OQ), .8 The erythroid precursors in the 8M in RA Refra ct ory thrombocytope nia is charac- and abnormalities of 5 aod/Of 7. The num- vary from decreased to rnatkedty increased ; terized by 2: 10% d ysplastic megakaryo- ber 01 reported case s of AN and is 100 m <tyseryltYopoie variestrern slight to mod- cv tee of at lea st 30 megakaryocytes low to allow for generalizations, although e ere. unequivocal evidence of dysp lasia eva luated : hypolcbate megakaryocytes, del(2Oq ) has been reported in AT 1 866. met be present in 10% or more erythroid b inucleate and multinucleate megakarye- 19381 . precursors. Dyserythropoiesis is manifest cytes and mrcromeqakarvocvtes are the principally by alterations in the nucleus most reliab le and reproduci ble featu res Postulated cell of origin includ in g budding, internuclea r br id ging , of mega karyocyte dysp lasia , Dyspl astic Haematopoietic stem cell. karyorrhexis. multinuclearity and mecato- megaka ryocyles may be more eviden t in blastoid ch anges: cytoplasmic features in. sections than smea rs and usually well Prognosis and predictive factors coos vacuolization and periodic acid-Schiff exceed the 10 % threshold . The mega- The clinical course is protracted ; the positivity, either diftuse or granular. Aing karvocvtes may be increased or de- median survival of patients wilh RA in one sideroblasts may be present but are <15% creased . The other myeloid ce ll lines do series was approximately 66 month s and iJ erythroid precursors. Myelob lasts ac- not show sign ificant dysplasia (<10%). the rate of progression to AML at 5 years ooun1 for <5% of the nucl eated BM cel ls, Distinction frem chronic autoinvnune was approximately 2% 178 . In another 21 The neutrophils and megakaryocytes are thrombocytopenia is cntc at and may be study, the median survival tor pat ients l:lmIaI or may show rnnimaJ dysplasia, but extremely difficult clinica lly and morpho- over 70 years 01 age with AA, RARS and ~ways < 10% in either cell line , The BM logi ca lly. Cytogenetic studies may be of MOS with del(Sq) was not sigml icantly biopsy is generally hypercellular due 10 consi derable aid in this distinclion 18661. different frem the non-affected population rcreased erythroid precursors. but may be 11371 1 Approximately 90-95% 01patients . rorrccenoiar or even hypocellular. Immunophenotype with RA have low or intermediate Interna- In refractory anae mia abe rrant immune- tional Prognostic Scoring System (IPSS) Refractory neutropenia ph enotyp ic features of erythropo ietic scores 1833, 833AI. Approximately 80-85% (lCD-O code 999 1/3) precursors can be found by flow cytometry have good to intermed iate cytogenetice Refractor y neutropeni a is ch aracterized ana lysis 15501 There are no d ata on RN . profiles 1782, 13711 Most patients with AT ,-- by~ 1 0% dysplastic neutrophils in the PB or and RT. have tow IPSS scores and 90% of the pa-s 3M; the dysplasia is principally manifesl as tients live more than two years 119381.a ru:::1ear hypoIobation and hypogranulation. Refractory cytopenia with unilineage dysplasia 95 .
  • 92. Refractory anaemia with R.P. Hasserjian N. Gatterman n ring sideroblasts J.M. Bennett A.D. Brunning J . Thiele Detinitioo of mitochondrial iron metabolism is sus- may be symptoms related to p rog ressive Refractory anaemia with nng stderoorasts pect ed . This de fect ma y be caused by iron overload . (RARS) is a myelodysp lastic syndrome soma tic mutations or deletion s in nuclear (MDS) cha racterized by anaemia. morpho- or mitochondrial DNA. Potentially analo- """"hologylogic dysplasia in the eryth roid lineage gous congenital d isorde rs inc lude the Patients typically p resent with norrTll>and ring eoercoteste comprising ~ 1 5% of Pearson mar row-pancreas synd rome , ch rom ic macrocytic or normochromicthe bone mar row (B M) erythroid precur- whic h features s.oerooiastc anaemia and normocytic anaemia. The red blood eelssors , There is no signif icant dysplasia in is caused by congenital large oeetcos of in the PB smear may manifest a d imor-non-erythroid lineages. Myeiobiasis com- mitochondrial DNA 1478/ . Somatic point phic pattern with a major population 01prise <5% allhe nucleated 8 M cells and mutations 01 mitochondrial DNA have normochromic red bkxxt cells and aare not present in the peripheral blood been ident ified in the BM 01 some patients minor population 01 hypochromic cells(Pe) , Secondary causes of ring sroero- with AA AS t7631 bu t it rema ins 1 be 0 Blasts are not present in the PB. The 8Mblasts must be excluded. established whether they cause the soeo- aspirate smear shows an inc rease in ery- b lastic p henotype 11 4221. Clona lity 01 throid precursors with erythroid lineageICD-O cod e 998213 CD34-positive progenitor cells and dysplasia. inc ludi ng nuclear lobation and erythroid and granulocytic elemen ts has megaloblastoid fea tures . G ranulocytesEpidemiology been demon strated in RARS patients by and megakaryocytes show no significantRARS accounts for 3-11% of MDS cases. x-cbrorosome inactivation analysis {549. dysplasia «10% dyspl astic forms).It occurs p rimarily in older indivi dua ls with 2 1261 Stem cells from AARS patients . Haemo sid erin-Iaden macrophages area median age of 60-73 years and has a d isp lay poor eryt hro id colony formation often abundant. Myelob lasts are less maosimi lar freq uenc y in males and females in vitro and manifest abnormal iron depo- 5% of the nucleated 8 M cells. On an iron-1267.782. 13711. sition at a very ea rly stage 01 erythroid stained aspirate smea r, 15% or more of deve lopment {444, 2 1781 . This evide nce the red cell prec ursors are ring srcero-EIOOgy suggests tha t RARS re prese nts a clonal blasts, as defined by 5 or more iron g ran-Ring sideroblasls represent erythroid pre- stem cell d efect that manifests as abnor- ules enci rcli ng one thi rd or more of thecursors with abnormal accumulation of iron mal iron metabolism in the erythroid lineage nuc leus. The 8 M biopsy is norrnocellulartowithin mitochondr ia. includi ng some depo- and results in ineffec tive eryt hropo iesis . markedly hyperceIlular. usually witha markedsited as mitoch ondria l ferritin 1352, 82 7f. erythroid proliferation. Meqakaryocytes arePrimary def ect s of haem synthes is (such Sites of involvement normal in number and morphology.as the a-amlnolevonruc acid synthetase The PB and BM are the prin cipal sites of Ring sid eroblast s are frequen tly observeddefect in hered itary X-link ed srderoblastc involvement. The liver and splee n may in other types 01MDS 1 776, 10781 For ex- .anaemia) ca n largely be exclud ed be - show evidence of iron over load. amp le , c ases with ring sideroblasts thatcause p rotoporphyrin IX, the end prod uct hav e exc ess blas ts in the PB or 8M areof po rphyr in synthes is, is not decreased Clinical features cl assifi ed as refractory anaemi a within RARS 11 2091 Furthermore , acqu ired . The presenting symptoms are related to excess of blasts (RAEB). When ring stoeromutations in g enes of the haem synthetic anaemia. which is usually of mode rate de- bl asts a re 15% o r more of the eryth roidpathway have not been demonstrated in gree; some pati ent s may additiona lly be precur sors but there are 10% or more dys-AAAS {20841 Therefore. a pr imary defect thrombocytopenic or neutrop eni c . There pl astic cells in any non-erythroid lineage.• A _Fig. 5.15 RefratQy..aema WItll rtog siderobIasts. A Blood smear wilh dmorphic red bklod eels and macrocyIeS (WrJItII-Giemsa). B 8lnI 1lWfOlf asptaIe smear stlowIWlg Imarked 8l)ttlroid proIiferallon with a d)5!JIBstlc Mderate bm (WrVrt-Giecnsa). C Ironslain d bone IlWfOlf iISpQI8 sIll:JrMng IU"IletOUS ring sdetoblasts.96 Myelodysplas!iC svnorores
  • 93. and bla sts are < 1% in the PB and <5% inthe 8M with no Auer rods or mo noc yto sis, 100the case is cl assi fied as refractor y cyto-penia with mullilineag e dy sp lasia (RCMD ),Such patients have infe rior surviva l to eopatients with AARS.tbHleoplastic causes 01ring sideroblasts . 0; .~ 60includ ing alcohol. toxins (lead and ben-zene). dr ug s (isoniazid), zinc aorrurustra- , 0 ---1....- RCMD with 2:15% RSton. copper defic ienc y and congenitalsderootastc anaemia, must be excluded1201. " ~ • Q. 40 ~RARSIrrrnunopheootypIn refractory anaemia with ring stdero- 20oests . aberrant immunophenotypic tea-lures of erythropoietic precursors can belound by flow cytometry analysis 15501. 0 0 100 200 300 MonthsGeneticsClonal chromosomal abnormalities areseen in 5-20% of c ases of AARS and, FIg. 5.16 Stn;vaI CtroeS aller long-lenn ~oI 161 patients WIth RARS and 318 RCMO patients WIltJ 215%mgwhen presen t. typic ally involve a single siderotlIasts (RSI. showing iltenor survival lor lIIe pallents WIth mg sideroblasts and nUtiIineage dysplasiachromosome 1267. 776. 7781 . (p:O.ClCIOOS)(Datafrom ltIe Dusseldorf UDS regislry),Postulated cell 01 orig inHaemato ielic stem cell. poPrognosis and p red ictive fac tor sApproximately 1- 2% of cases of AAA Sevolve to ac ute mye lo id leukae mia. Thereported ove rall median survival is69- loa months 1 549, 7781. Aefractory anaemIa with ring soercoiests 97
  • 94. Refractory cytopenia with multilineage R D. Brunning J ,M . Bennettdysplasia E. Matures A. Orazi J.w. Vardiman J. ThieleDefinition b lasts in the PB, <5% in the BM, and noRefractory cytopenia with multilineage Auer rod s should be classified as refrac -d ysp lasia (ACMD) is a type 01 myelodys- tory ana em ia with excess of blastsplastic syndrome (MOS) with one or more (RAEB)- l ; cases with 1% blasts or fewercytopenias and dysplastic changes in tNO in the PB and <5% blasts in the BM, andor rrore of the myeloid lineages: erythroid . Auer rods should be classified as RAEB-2 ;9mnulocytic. n-egaka<yocytjc 118641. rtere cases with 1% blasts in the PB and <5%are < 1 % blasts in the peripheral blood in the 8M and no Auer rods should be(PS) and <5% in the bOne marrow (8M) ; classified as MDS-U. Some cases ofAuer rods ere not present and the mono- RCMD have 2:15% ring sideroblasts (782 .cytes in the P8 are less than l xHJI.. The 137 11 .recommended levels for defining cytope-nias are haemoglobin < lOgfdL absolute ICD-Ocode 998513neutrophil cocnt <1.8xl()9/l and plateletcount <100xl()11I.I633. 833A1 . However, Epid emiologyvalues in excess 01 these thresholds are Refractory cytopenia With multilineagenot exclusionary of a diagnosis of MDS if dysplasia occurs in older ind ividuals: thedefinitive morphologic and/or cytogenetic median age is approximately 70 years.findings are consistent with a diagnosis. There is a sligh t predominance of males.e.q. complex cytogenetic abnormalities . The peak incidence for males is 70-74The thresholds lor dysplasia are ~10% in years, for fema les 75-79 years (7821. Iteach of the affected cell lines. In assess- accounts for -30% of cases of MDS 1782.ing dysp lasia it is recommended that 200 137 11 .neutrophils and precursors and 200 ery-throid pre cursors be evaluate d in smear Sites of involv ement ....... Fig. 5.1 Refractooy ~ withrn.J~~and /or treph ine imprint preparations. The Blood and bone ma rrow Bone marrow sme shows eviOenCe 01 dyspasia...bl:tl arneutr oph il dysplasia may be evaluated in ee erythroidprecursors andthe neutropnils. The maIttPB or BM smears. At least 30 meg akary- Clinical features neutrophils aresmall andMvallypolobulated rn.cIeI.cc ytes should be evaluated for dysplasia Most patients present with evidence 01in BM smears or sec tions, In some ca ses, BM failure with cy topenia 01two or moredysplastic meg akaryocyt es may be mor e myeloid cell lines. hypo granulation and/or nuclear hyposeq.readily identif ied in sec tions than smears, ment ation with ma rked clump ing of theIn particul ar the presenc e of micro- Morphology nuclear ch romatin (p seudo Pelqer-l-iuetmegakaryocyte s should be noted . Cases The BM is usually hypercellular. Neu - nuclei), The nuc lear hyposegm entationwith multilineage dyspl asia and 2-4% trophil dy splasia is cha racte rized b y may occur as two clumped nuclear lobes con nec ted by a thin chromatin strand (ptoce-nez type) Of marked ly clumped non-lobated nuclei , Myeloblasts account for <5% of the 8 M ceus. In some cases there is a marked inc rease in erythroid precu rsors . Erythroid p recursors may show cytoplasmic vacuo les and marked nuclear irregularity, inclu ding internuclear chromatin bridging, multilobation, nuclear bu dd ing, multmucleation and megalo- brastord nuclei. The vacuoles are usually poorly defined and dissimilar to the sharply demarcated vacuoles observed in toxic alterations such as alcoholism The vacuoles may be pe riodic acid-Schlll (PAS) positive; there may also be diffuse cytoplasmic PAS positivity. In RCMD,98 Myek:!dYSplastlC syndromes
  • 95. variable numbers of ring stoercorasts may Immunophenotype Prognosi s and pred ictive factorsbe identified Megakaryocyt e abnorma li- See Chapter on mye lod ysplastic syn- The clinical course varies. The majority ofties which may be obse rved inclu de non- oromesrneo otasms. overview. patients wilh RCMD has Internationallobated nuclei, nvpotonered nuclei, Prog nostic Scoring System (IPSS) scoresbinucleate or multinucleate megak ary- Genetics in the intermediate category 1833, 833AI.ocvtes and micromegakaryocytes; the mi- Clonal cytog enetic abnormalities including Prognosli c factors relate to the degree otcromegakaryocyte is defined as a trisomy 8, monosomy 7, del(7q). mono- cytopenia and dys plasia . The frequencymegakaryocyte approximately the size of somy 5, del(5q ), and del(2Oq), as well as of acute leukaem ia evolution at two yearsa promyelocyte or smaller with a non- com plex karyotyp es, may be found in up is - 10% in RMCD 17821. The overall me-lobated or bitobed nucleus and is the to 50% of patients with RCMD {782, 8331. dian survival is approximately 30 rron ms.most reliab le and reproducible dysplastic Patients with complex karvorvpes havefeature in the megakaryocyte series Postulated cell of origin survivals similar to patients with refractory{1 4201_ Haematopoietic stem cell . anaemia with excess of blasts (AAEB) 17821. Refractory cvtooeoa With multJ!ineage dysplaSia 99
  • 96. Refractory anaemia with excess blasts A.Orazi R D. Brunning R P. Hasserjian U. Germing J. ThieleDefinitionRefractory anaemia with excess blasts(RAEB) is a myelodysplastic syndrome(MDS) with 5-19% myeloblasts in thebone marrow (BM) or 2-19% blasts in theperipheral blood (PB) Because of differ-ences in survival and inc idence of evolu-tion to acute myeloid leukaemia (AML).two categories of RAEB are recognized:AAEB-l, defined by 5-9% blasts in theBMor 2 -4% blasts in the PB, and RAEB-2 ,defined by 10-19% blasts in the 8M or5-19% blasts in the PB 18331. The pres-ence of Auer rods in blasts qualifies acase as RAEB-2 irrespective of the blastpercentage 17811.ICD-O code 998313Ep;demkllogyThis disease affec ts primarily individuals FIg. 5.19 Relractoryanaemia Wl1tJ excess b1asts-1(RAEB-1J. Bone rnatrOWsmear. The malJ.le ~ IIhsc.over 50 years 01 age . It accounts lor ap- show nuclear hypolobulabon (pseudo Pelger-Hll8I nuclei) and cytoplasmic hy arnunty. pogrproximately 40% of all patients with MOS.Etiology show d yserythropoiesis including the normocellular or hvpocenuar. RAEBcasesThe etiology is unknown. Exposure to en- presence of ab no rmally lobulated nuclei with hypocellular 8M represent only avironmenta l toxins, including pesticides, and internucl ear bridging, Granulopoiesis small proportion of ca ses of hypoplasbCpet roleum derivatives and some heavy is frequently incr eased and shows var i- MOS, since most of these cases do rdmetals inc reases risk, as d oe s cigarette able deg rees of dys p lasia. This is cha rac- show an increased numbe r of blasts anasmok ing 12113AI. terized primarily by sma ll size neutrophils belong to the g roup of refractory cvtooere with nuclear hypo lo bation (pseudo with unilineage dys plas ia (RCUD) or lessSites of Involve me nt Pelq er-Hoe t nucl ei) or nucl ear hype rseg- common ly to refractory c yto penia witnBlood and bone marrow , me ntation , c ytop lasm ic hypogranularity mu ltilineage dy sp lasia (RCMDl , The 8M and/or pseudo Chediak-Higashi g ranules. bio psy ca n be very useful in documentingClinical features Megakaryopoiesis is va riable in quantity the presence of an exc ess of blasts per-Most p atients initially present w ith symp- b ut is frequentl y no rma! to increased. The ticula rly in cases w ith subo ptimal aspiratetoms rela ted to BM fail ure , includ ing megakaryocyt es often show a tend enc y to smears such as those assoc iated wim aanaemia, thrombocytopenia and neutro- c luster. Oysmegakaryopoiesis is a lmost hypocellular and/or fib rotic BM. Blastsi1pe nia. inva riably present and is usually cha rac- AAEB of ten tend to form cell clusters II terized by the p rese nce of a bnormal aggregates that are usually located a~""""",Iogy forms predomin antly of small size, incl ud - rom bone trabeculae and vascular sncThe PB sme ar freq uently shows abnor- ing micromegakaryocytes 122261. How- teres. a histologic find ing formerly referredmali ties in all th ree myeloid cell lines. eve r, megakaryocytes of all sizes as well to as abnormal localization of immatureincluding red cell anisopoikilocytosis. as for ms wi th multip le widely-separated precursors (AlIP). Immunohistochemicallarge, giant or hypogranular platelets and nuclei can also occur. The BM biopsy staining for C034 may be particulartyabnormal cytoplasmic granUlarity and shows alte ration of the normal tnstc- helpful in their identification.nuclear segmentation of the neutrophils. topography. Both erythropoiesis andBlasts are commonly present. The BM is megakaryopoiesis appear frequently dis - RAEB wilh fibrosis (RAEB-F):usually hyperceHular. The degree of dys- located towards the paratrabecular areas In about 15% of patients with MOS, eeplasia may vary. Erythropoiesis may be that are normally predominantly occupied BM stews a sign ificant d eg ree of relCl.irlincreased with macrocyticlmegaloblastoid by granulopoietic cells. fibrosis . Such cases have been termedchanges . The erythroid precursors may In a minority of cases the BM appears MDS WIth fibrosis (MDS-F) (1246. 1400/.100 MyelOdysplastiC syndromes
  • 97. Since myelQfibrosis can be seen also in Irrmunoph enotype Postulated cell of origincases otmerapv -rerateo MOS, myelop ro- Flow cytometry in RAEB often shows Haematopoietic stem ce ll.liferative neoplasms, and, rarely, in reac- increased numbers 01 cells pos itive fortive dyshaematopoietic con ditions (e·9 precursor ce ll assoc iated antigens CD34 Prognosi s and pledictive factorsHIV·related myelopathy) these conditions and/or C0 117. These cell s are usually Refractory anaemia with excess blasts isneed to be excluded. Because of the lack positive for C038. HLA-DR and myeloid- usually char acterized by prog ressive BMof consensus on the degree of fibr osis assoc iated antigens CD13 and/or CD33 . failure with increasing cytopenias. Ap-necessary to characterize a case as Asynchronous expression of granulocytic proximately 25% of cases 01 RAEB-l andMDS-F, it is stilt unclear whether fibrosis maturation antigens CD1S, C011b and/or 33% of pat ients with RAEB-2 progress torepresents an indepe ndent prognostic COOS can be seen in the blast population. AML; the remainder succu mb to the parame ter 1 2083 1. The cur rent wo rking Aberrant expression 01C07 on blast cells sequelae 01 BM failure. The median survival definiloo of MOS-F requires diffuse coarse is seen in 20% 01 cases and C056 is is approximalely 16 months for RAEB-1 reticulin fibrosis with or without coocomilant present in 10% of cases . while exp ression and 9 months for RAEB-2 17811 CD7 . collagenizalion , associated with dysplasia of other lymphoid markers is rare {1210. exp ression has been assocrateo within at least two cell lineage s 1 2083, 23121. 1623J, poo r prognosis {16231. Most of the cases def ined as MOS· F In tiss ue sec tions, C034 immunoh isto- RAEB-2 patients with 5- 19% blasts in the belong to the RAEB category (RAEB-F), chemistry may be used to co nfirm the PB have a median survival of 3 months The presence of an excess of blasts in presence of an increased number of similar to that of myelodysplasia-related these cases ca n usually be demonstrated blasts; it allows the apprec iation of their AML 1 t 41 , In contrast, cases defined as 21 using immunohistoch emistry. particularly arrangement into clusters or agg regates, AAEB-2 based only on the presence of for CD34. The BM smears are usually a cha rac teristic finding seen in most of Auer rods . have a prognosis which is inadequate. A cha ract eristic finding in the cases of RAEB 1 20501. Antibodies similar to that seen in cases of RAEB-2 RAEB-F is an increased number 01meg a- such as C061 or C042b can aid in the with 2-4% periphe ral blasts (median sur- keryccv tes with a spectrum of cell size identification of micromegakaryocytes vival. 12 months) 121141. (including micromeg akaryocytes) and a and other small dysplastic forms. wh ich high degree of dysplasia 112461. Cases of are particu larly numerous in cases of RAEB·F may morpholog ically over lap RAEB-F 11246, 22261_ acute paomveiosts with myelofibrosis (APMF) previously referred to as acute Genetics (malignant) myelofibrosis. APMF is d is- A variable percentage of cases of RAEB ne t from RAEB-F by its abrupt onset with (30- 50%) have clonal c ytogenetic abnor- ever and bone pa in 11651 , 22251. mal ities, including +8 , -5, de l(5q ). -7. del(7q) and del(2Oq). Complex karyo- types may also be observed 1 7821 . Refractory anaemia with excess blasts tOl
  • 98. Myelodysplastic syndrome with RP. Hasse rjian MM LeBeau isolated del(5q) AF. li st J.M . Bennett J . ThieleDefinitionMveiccvsoiasnc syndrome with isolateddel(Sq) is a myelodysplastic syndrome(MDS) cnaractertzeo by anaemia with orwithout other cvtopenrasand/or thrombo-cytos is and in which the sole cytogeneticabnormality is del(Sq), Myeloblasts con- ,. • , .prise <5% of nucleated bone marrow (8M)cells and < 1% 01 pe ripheral blood (PSIleukocytes and Auer rods are absent.SynonymMyeIodyspIastic syndrome with 5Q deletion(Sq- syndrome) . non-lobated and hypolobated nuclei. In generally not in mature lymphoid cellsEpidemK>logy contrast, dysplasia in the erythroid and 139.2191.MDS with isolated del(Sq) occurs more myeloid lineages is uncommon 1257.oflen In women, with a median age 0167 794}. The term "Sq- synd rome - has been Prognosis and predictive fact orsyears. used to desi gnate a subset 01 cases with This disease is associated with a rrecen macrocytic anaemia. normal or eleva ted survival of 145 months, with transformatiooEtiology platelet count and BM erythroid hypoplasia to acute myeloid leukaemia occurring IIPres umed loss of a tumou r suppressor 1257,23621. The number of blasts in the <10% of patients 17941. Patients withge ne in the d eleted regioo . Possible ca n- BM is <5% and in the PB is < 1%. del(Sq) associated with other chrorTlOSlmlldi dates include the early g rowth respo nse abnormalities or with excess blasts have 1 (EGR 1) and c -ceterm (CTNNA I) genes Genetics an inferior survival and are excluded frOOIand as-vet-untcennted genets) in 5q32 The sole cytogene tic abnormality involves this diagnosis 17941. Recently. the thali a;1256, 1075, 1324). The RPS14 gene that an interstitial deletion 01 chromosome 5; mide analogue lena fidomide has beenencodes a ribosomal protein has been the size of the del etion and the breakpoints shown to benefit MDS patients with isolatedpropo sed as a can didate in the Sq- syn- are variabl e, but ba nd s q 31 · q33 are del(Sq) as well as d el(5q) with additionaldrome, raising the possib ility that a defect invariab ly deleted . If any ad ditional c yto- cytogenetic ab normalities. Transfusionin ribosomal p rotein func tion ca uses that ge netic ab nor mality is p resent (With the inde pendence was achieved in two thirdsdi sorder 1256. 635 , 1075. 1324 1. exception of a loss of the Y chromosome), of p atients and was c losely linked to the case should not be p laced in this cat- suppression of the abno rmal clone (795,Sites of involvement eqoey 11 has bee n recen tly reported that a 13201Blood and bone ma rrow, small subset of patients with isolated del(Sq) m ay show a concomitant JAK2 V617FClinicalleatures mutation. Until more data are collected forThe most common symptoms are usually such cases and their clinical behaviour andrelated to anaemia. whic h is often severe respon se to therapy such as lenalidomideand usually macrocytic. Thromboc ytosis is are clarified. it is prud ent to classify lhem aspresent in one third 1 one half of patients. 0 MDS with isolated de~5q) (rather than in thewhile rnromcoocytopenle is uncommon MDS/MPN category) and to note the pres-{794, 14171. ence of the JAK2V617F in the diagnosis 110051.Mo<phologyThe BM is usually hypercellular or norma- Postulated cel l of origincellular and frequently exhibits erythroid Haernatoootetrc stern cell . FISH analysishypoplasia 123621. Meg akaryoc ytes are has confi rme d p resence of the del{Sq)increased in number and are normal to abnormality in differentiating erythroid.sfil.:t1tIy decreased in size withconspicuwsIy myeloid. and megakaryocytic cells, but102 MyelodysplastJc Syndromes
  • 99. Myelodysplastic syndrome, A.Orazi AD Brunningunclassifiable I. Baumann R.P Hasserpan .DefinitionMyelodysplastic syndrome. unclassifiable(MDS-U ) is a subtype 01 MDS which ini-t~1y lacks findings appropriate for classi-fication into any other MDS category -- There are no specific morphological lind- iogs. The diagnosis of myerocvsplasnc syndrome, unctasslnabie. can be made in the followi ng instances: Genetics See Table 5 .04. Postu lated cell of origin Haematopoietic stem ce ll.Three possible situations which qualifypa tents tor inclusion in this category are 1. Patients with the findings 01 refractory Prognosis and predic tive factorslisted under -morp hology·. cytopenia with unilineage dysplasia If characteristics of a specific subtype of (RCUO) or refractory cytopenia with rn.Jlti- MDS develop later in the course 01 the 9989/3 lineage dysplasia (RCMD) but with 1% disease , the case should be reclassified blasts in the P8 qualify for MDS-U 111651. accordingly. In cases diagnosed as MOS.Sjrooym U. it is unknown both the percentage 01Uyelodysplastic syndrome, NOS. 2. Cases of MOO with tXlihneage dySplasia patients which translorm to acute myeloid which are associated with pancytopenia. leukaemia as we ll as the disease survival .EpOdemk>logy In contrast. the RCUD category only allows Cases with features otherwise consistentThe incidence of mvetodvscrasuc 5YO- for a single cytopenia or bi-cytoperna . WIth a diagnosis 01 RCUD Of ACMO. but incone. uoctassmame. is unknown. which 1% blasts are detected in the peri- 3 . Patients with persistent cvtooemats) pheral blood, have been shown to have aSites of irwotvement with 1% or fewer blasts in the blood and prognosis which is intermediate betweenThe peripheral blood (PB) and bone mal1C1W fewer than 5% in the BM , unequivocal ACUO (or ACMO) and that of refractory(8M) are the principal sites of involvement. dysplasia (Table 5.03) in less than 10% of anaemia with excess blasts (AAEB) the cells in one or more myeloid lineages. 11 1651.Clinical featu res and who have cytogenetic abnormalitiesPatients present with symptoms similar 10 considered as presumptive evidence 01 MOOn ose seen in the other myetcovsprasnc (Table 5.04) are p laced in this categorysyndromes. MDS-U p atients should be carefully fo llowed for evid enc e of evolution to a more specific MDS type. Myelodysptasttc syndrome. unclaSSiflable t03
  • 100. Chi ldhood myelodysplastic syndrome I. Bau mann C,M. Niemeyer J .M , Bennett K. ShannonMyelodysplastic syndrome CMOS) is very BM. For example, the subtypes 01 refractoryUflCOrTlfl"lOf1 in children, accounting lor less anaemia with ring stoeroblaets and MDSthan 5% of all haematcooenc neoplasms associated with isolated del (Sq) chromo-in patients less than 14 years of age somal abnormality are exceedingly rare in(Table 5 .06) 1908. 910 , 1595A, 2079AI . chil dren 11595A1. Isolated anaemia, whichThe de novo or primary form of MDS in is the major presenting rnamtestatton ofchildren should be distinguished from refractory anaemia (RA) in adults, is un-cases of "secondary MOS· that follow COlTIllOO in chil d ren, wto are more likelycongenital or acquired bone marrow (8M) to present with neutropenia and thrombo-failure syndromes and from therapy· cytopenia 1908, 11091. In addition, hypo-related MDS that tollows cytotoxic therapy cellularity of the BM is more commonlytora previous neoplastic or rco-reootastccondi tion. Furthermore. although MOSassociated with Down syndrome hasbeen reported to account lor 20-25% 01 observed in childhood MDS than in older patients. Therefore, some chi ldren have findings that do not readily fit into the "low grade" MDS categories. To address these • ~ . IQ 5J l Relractory~ddikhxld(RCC~_ marrow smear showing abnormal nuclear IctUabcwl d an twyttYopoietIc precursor eel alld a smaI megaQ"r-cases of childhood MDS in the past differences, a provisional entity, refractory ocyle WItIl a IJi.lobed 1IUdeus,{2079AI, this disorder is now considered cytopenia of childhood (RCC) is intro-as a unique biologic entity synonymous duced and defined below.with Down syndrome-related myeloid For ch ildren with MOS in whom there are Refractory cytopenia of childhood (RCC)leu kaemia and cnstmct from other cases 2-19% blasts in the PB or 5-19% blasts inof chil dhood MDS (See Chapter 6). the BM . the same criteria utilized for adults DefinitionMany of the morphologic. immonopheno- with refrac tory anaem ia with excess blasts Refractory cytopenia of childhoocl (RCC}1Stypic and genetic features observed in MDS (RA EB) should be ap pl ied . Cu rrently, in a mveioovsotastc syndrome (MDSl char·in adults are also seen in ch ildhood forms contrast to adult MOS, the re are no avail- actenzeo by persistent cytopenia with <5%of the d isea se b ut the re are some signifi- ab le stu di es that have investigated the blasts in the BM and <2% bla sts in the PBc ant d ifferen c es reported , part ic ularly in prognos1ic sig nific ance of distinguishing {908) . Although the pre sence of dysplasiapat ients who do not have increased RAEB-1 and RAEB-2 in chil dren, bu t it is is required for the d iagnosis, the cytologicalblasts in the ir pe ripheral blood (PB) or rec ommended th at this distinc tion be evaluation of dysplasia by itself const itutes made for future investiga tion. Children with only one aspect of the morpho logical diag-Table 5.06 Ir.cKIence of haematoklgical malignancies in RAEB generally have relativ ely stable PB nosis of RCC , The evaluation of an ade-children 0 - 14 years, Combined data from Dtlnmark. co unts for weeks or months , Some cases q uate BM trep hine biop sy specimen is1980-1991 and British Columbia 1982-1996(907, 908}. d iagnosed in children as ac ute myeloid indi spensable for the d iagnosis 01 RCe in leukaem ia (AML) with 20-29% blasts in the c hildren, About 75% of ch ildren with RCe N % Incidence PB and/or BM that have myelodysp lasia- show co nsi de rable hypocellularity 01 the AU 915 79 38.5 related c hang es. includ ing cases w ith BM 117841. Conseq uently, it may be very AMl1 115 11 5.4 myelodysp lasia-related c ytogenetic ab- cha llengin g to d ifferentia te hypocellular "lOS 38 4 1.8 normalities (See Cha pte r 6 ) may also RCC from other BM failure disorders, es- Myebd leuk.aemia of OS 19 2 0.9 have slowly progressive d isease. These pecially from acquired aplas tic anaere JMMl 25 2 1,2 c ases, co ns idered as refract ory anaemia and inherited BM failure disorders. Down CMl 13 1 0,6 with exce ss blasts in transformation in the syndrome-related myeloid neoplasms are French-Amer ican -British cooperative clas- excluded from this diagnosis. The WHO VIET 3 o 0.1 sification. may lack the cli nical features of Working Group assigned RCC to a groop Unclassified 3 o 0.1 acute leukaemia and be have more like of provisional entities. MOS than A ML 19081. thus follow-up PB T"," 1031 100 48.1 an d BM studies are often necessary to ICD-{) code 998513 ALl. acute IyrnpIlobIaSbC leukaemia; AML. acute measure the pace of the d isease in such myeloid leukaemia; MOS, ~SbC s)lklrome; c ases. Children who present with a PB Synonym JMML,;.wetiIe m~ leukaemia: CUl . and/or BM disorder associated with Refractory anaemia of childhood. etworic myelogenous leukaemia. PII. poIytytllaeITia t(8;21)(q22;q22), inv( 16)(p13.1q22) or vera; El essenbal ttvorrtlocyIII t( 16; 16XP13. 1;q22) or t( 15;17Xq22;q 12) Epidemkllogy , Exdudng Down 5)I»ome (OS) I per n-.on poptAalJon peryear should be considered to have A ML re- RCC is the most corrmon subtype 01 MDS gardless of the blast count in childhood accounting for about 50%ct104 Myelodysplastic syndromes
  • 101. c ytop lasm may be note d . Blasts are absent or account for less than 2% of the white blood cells . On 8M aspirate smears dysplastic changes should be present in two ditlerent myeloid cell lineages, or exceed 10% in one sing le cell line (Table 5.07). Erythroid abnormalities inc lude nuc lear budding , mcmnucreanty karyorrhexis , internuclear bridg ing. cytoplasmic granules and macr0- cvnc Changes . Cells of granulocytic line- ., age ma y extubtt hyposegmentation with • ./ p seud o-Pelqer-Huet nuclei . hypo-fagran- < f , .. •• ularity of the cyt oplasm , mac rocytic (giant) bands and cyt oplasmic-nuclear maturation .. asynchrony. Myeloblasts account lex" fewer ~ • . I ....~ ~ ~ 1- than 5% of the 8M cells. Megakaryocytes are usua lly absent or very low in nt.rn ber. The detection of micromegakaryocytes is a strong ind icator 0 1 RCC . Ring sioero- bla sts are not fou nd . In RCC with norma- Of hypercetlular 8M specimens there is slight to moderate inc rease of erythropoiesis with accumula- tion o f immature precursor cells. mainly proerymrootaste. Increased numbers of mitose s indicate ineffective erythro- po ies is. Granu lopoies is appea rs slightlyire cases 11704, 1784 /. II is diagnosed in Morphology 10 moderately decrease d and ce lls ofall age groups and affects boys and gi rls The classica l p ictu re of RCC is a PB granulocytic lineag e are loo sely scat-with equal frequency 111091. sme ar that shows red blood cell tered. Blasts ac count for less than 5% of antsopolknocytosts and macrocytosis. the 8 M cells , and C034 staining on theStes of involvement Anisochromia may be present. Platelets biopsy is useful for verification of the blastBlood and 8 M are alw ays affected. Gen - often di splay anisocytosis and occasion- percentage. Megaka ryoc ytes may be nor·efally. spleen. liver and lymph nod es are ally g iant p late lets can be de tected. ma l, decreased Of incre ase d in numberrot sites of initial ma nifestation . Neutrope nia wit h pseudc -Pelg er-t-luet and display dys plasia with non-lob ulated nuclei and/or hypogranularity of neutrophil nuclei. abnorma lly sep arated nucl earClinical featuresThe most common symptoms are malaise, Tab 5.07 Minimal diagnostic criteria for reffactory cytopenia of childhood. lebleeding , fever and infection /1109). lym-phadenopathy secondary to local or Erythropoiesis Granulopoiesis Megakaryopoiesissystemic infec tion may be present, but Bone marrow Dyspl astic changes Dysplasbc changes" in at Unequivocalhepatosple nomegaly is ge nerally not a aspirate andlor megaloblastoid 1 8ast 10%of granulocytic micromegakaryocytes,feature of RCe , In up to 20% of p atients, changes in at least 10% precursors and neutrophils: othefdysplasticchangesleocjrucal signs Of symptoms are reported of erytlroid PfeoJ~ <5%blasts in variable numbers11 109/. Congenital abnormalities of differ- Bone marrow A lew dusttlSof at least20 No minimal diagnostic cmeria UnequiYocalent organ systems may be present. biopsy erythroid precursors. micromegakaryocytes:Three Quarters of patients have a platelet Stoll in maturatiOn with irnrllJnohistoctlemistry iscount be low 150 x10 9/L. whi le anaemia increased numbers of obIigab) (COOl , CD41 ).with a haemoglobin concentration 01lessthan 10 g/d L is noted in aboul half of the 10 ofmitoses. lncmased I1UITtlers oltlerdysplasti: cIIange5t ill variable I1lSI1bersaffected children 111091 Mac roc ytosis of . Peripheral blood Dysplastic changesfed cells evaluated accord ing to thepatients age is seen in mos t The wh iteblood count is generally decreased withsevere neutropenia not ed in about 25 % "" .... nat I8ast10%of neutrophis; • AbnormaIIIIdear lobulation, mutIirKIdear oeh. IlUdear bfidge$.11 1091. r Pseu:Io-PeIger-HlJiit eels. tlypo-or agrardanly, IJifl b8rlds (In cases of severe neutropenia lI»s crilena may nol be fuIIiIed ).Etiology f Megakaryocytes of vanabIe see WIttl $&p8r31ed nuclei orround IlI,dei.Theabsence of megak¥yIX:yIes "not emude refraclofy C)IOPelIia of chitJlood.The etiology is unknown in most cases. Childhood myeocvsotasuc svocrore 105
  • 102. bbl, 5.08 thereby mimicking RCC (Table 5.09). InComparison Of rnlIIphologicaI cnlefiaaI hypoplastic refracby cytopeoiaof childhood and aplasticanaemia inchildhood the absence of a cytogenetic marker the R,1ractofy cytopenil of childhood clinical course of cases suspected lX RCC has to be carefully evaluated before -- lbIe m.tm::lW. . C)tc*lgy a clear-cut diagnosis can be made. rte -- -- haematological differential diagnosis .... Pattry dcstrtluIion ciuoes acquired aplastic anaemia. riter· _d_ lell shift .......,..." ited 8M failure diseases and paroxysrral nocturnal haemoglobinuria (PNH). In ceo- trast to RCe. acquired aplastic aneere ~-­ Agranuiabon ofcytoplasm presents with adipocytosis of the 8M spaces with few scattered myeloid cells Ni.dear<ytoplasmlc malurabondefects there are no erythroid islands wllh increased numbers of immature erythro- Marked dea8ase M~ blas ts, no granulocytic dysplasia and no Dysplastic manges MulI ~e separated nuclei Miaomegakaryocytes Small round nuclei micromegakaryocytes (Table 5.08). CO< trary to wnat is sometimes reported in adUls Lymphocytes May be increased focally May be incr ased e with aplastic anaemia, at presentation or dispersed acquired aplastic an aemia of childhood does not have mega loblastic features; IQl. C034+ cells Noincrease lowing immunosuppressive therapy, the histological pattern of acquired apiasic anaemia can no longer be separated fnm Aplastic lNemia in childhood tha t observed in RCC. The inherited au failure oeoroers such as Fanconi ereera BoN tIJafJDW ISpI(BIe ~ ovskeratosrs conqemta . Shwachmar- Diamond syndrome, amegakaryocytC -- l.Icting or single smaI bcus lICkflg or Y8IY lew eels, WIthool. thrombocytopenia or pancytopenia WlIh Ie5slhat110cels W11tl dysplasia or megalobIastlid change radioulnar synostosis show overlap morphological features with ACC, They I.JIc:UIg or ~ decrease, have to be excluded by medical hisl~ phySical exemoanoo and the appropraale - Y8IY lewsmalloci NIth maturation laboratory and molecular studies belen l.adUng orY8IY few, no dysplastlc a definite diagnosis of RCC can be made The clinical picture of PNH is rare in C/"Ml(j. hood. although PNH clones in the ab- -"" May be increased bcally Of May be increased sence of naemoivsts or thrombosis may be observed in children with RCe 122921 C034+ cells No increase The relation between RCe with two (It" mo re dysplastic lineag es and retractor cy topen ia with mu llilineag e dysplasia (RCMD) has not vet been evaluated,lobes and charact eristic micromegaKaryo- establis hing the diagnosis, Multiple sec- Currently il is recommended that childrencytes. There is no incr ease in reticulin tions prepared from the biopsy may be who otherwise fit the criteria for RCMD befibres. helpful in roermtcanoo of abnormal rneqa- considered as RCC until such studiesThe majority of patients with RCC show a karvocytes and immunohistochemistry to cla rify whether the number 01 lineagesmarked decrease of 8 M cellularity, down identify mictomegakaryocytes is obligatory. involved is an important prococsc10 5-10% o f the normal age matched Fatty tissue between the areas of haemato- discriminator in childhood MOS.veroe. The morphologic findings are sim- poiesis can mimic aplastic anaemiailar to those observed in the normally (Table 5.08). Thereforeat least two biopsies Immunophenolypecellular Of hypercetlular cases. Immature at least two weeks apart are recom- Mlcromegakaryocytes can be missecerythroid precursors form one or several mended to facil itate the detection of easily in H&E stained 8M trephine biopsyislands consisting 01 at least 10 cells . This representative 8M spaces containing foci sectcos but can be more readily awe-patchy pattern of evtreoooests is usually of erythropoiesis. ciated by the expression 01 platelet g/y(»accompanied by sparsely distributed proteins like C061 (glycoprotein lila), C04Igranulopoiesis. MegaKaryocytes are sig. Differential di agnosi s (glycoprotein lib/lila) or von Willebranclnilicantly decreased or absent. Although In children, a variety 01 non-haematological factor. Myeloblasts do not account tamicromeqakaryocvtes may be rare or not d isord ers such as viral mtecuons. nutri- more than 5% of the 8 M cells , and oetec-always found, they should be searched tional deficiencies and metabolic diseases tton of 5% or more CD34, mvetooeroelor carefully as they are impo rtan t in can give rise to secondary myelodysplasia, dase, lysozyme and CD 117 positive biaS!106 Myelodysplastic syndromes
  • 103. cells may lnc ncate progression to high Table 5.09grade MOS. Clusters of myeloblas ts are Dfsofders which maypresent witll morp hoj ogic.a lleal~ res indisbnguishable from refr actory cytopenia ofct1ildhood,-ot seen in ACC. Infectioos (e.g, c:ytomeo;lalovirus, herpes Wuses. parvovirus 819, YiscerailelsnmaniasiS) Vrtamin detiOeocy (e,g.deficiency of vitamin B12,Iola Yilamln E) le,Genetics Metabolic: disorders (e.g, mevalonatemase delk:iency) The genetic changes predisposing to!.lOS in childhood remain largely obscure. Rhel.maliC diseaseThe presumed underlying mechanism A.utoirmuIe I)mphoproIIferative dISOrders (e,g, FAS deftciency)may also give rise 10 subtle phenotypic Mllochondrial deleloos (Pear9on S)YIdrome)abnormalihes noted in many children with ~ bone marrow laikJre disorders(e,g Fanconi anaema. dyskeratosis congeniIa, 5hwactmam-OiarnondMOS. Monosomy 7 is the most common syndrome , amegakaryocyIit~,1hrorTtlocytope WI1h absent radii radioulnar syMSlO$lS. ,cytogenetic abnormality /1 109, 1704, Sedtel syndrome)17841 . Other cytogenetic abnormalities P~nochrnaI ~ (PM-I)IlChJding complex karyotypes may also ~ apIasbc anaemia dlmg haemalologicallllCOYllfybe observed. Most cases of ACC show arnmal karyotype irrespective 01 8M eel-ltarrty. There is no difference in morpho- Spontaneous disappearance of mono- An expectant approach with careful ob-lOgy between cases with Of without somy 7 and cytopenia has been reported servation may be reasonab le for patients-oonosomy 7. in infants, but remains a rare event I t3801. in the absence of transfusion requirements. In contrast to mooosomy 7, patients with severe cytopenia Of infections. BecausePtlstuIated cell of origin trisomy 8 Of norma l karyotype may expe- early 8M failure can at least in part be me-saematopoenc stem celt with multihn- riencea long stablecourseof their disease, diated by t-een immunosuppression ofeage potential , Currently, haematopoietic stem ce ll trans- baenatoooese. irrmunosuppressive ther- plantation (HSCT) is the only cu rative apy can be a successful therapy strategyPrognosis and pred ictiv e factors therapy and is the treatment of choice for for improving outlook in some children(aryotype is the most important factor patients with monosomy 7 or complex with ACC 1 2033, 24711 .or progression 10 advanced MOS. Pa- karyotypes early in the course of their dis-tents with monosomy 7 have a sign ifi- ease . In view of a low transplant-relatedcantly higher probability of progression mortality HSCT can also be recorsrenoedf an patients with other chromosomal ab- for pa tients with other karyotypes if a SUIt·rcmannes or normal karyotype 111091. able donor is available /1784 . 21041. Childhood myelodysplastlc syndrome 107
  • 104. CHAPTER 6 Acute Myeloid Leukaemia and Related Precursor NeoplasmsAcute myefoid leukaemia with recurrent genetic abnormalitiesAcute myeloid leukaemia with myelodysplasia-related changes lllerapy-related myeloid neoplasms Acute myeloid leukaemia, not otherwise specified Myeloid sarcoma Myeloid proliferations related to Down syndrome Blastic plasmacytoid dendritic cell neoplasm
  • 105. Acute myeloid leukaemia D .A, Arber R D , Brunning J.w. Vard ima~ A. POrNItwith recurrent genetic abnormal ities M .M. le Beau B , Falini J. Thiele CD. BloomfieldAML with balanced Epidemiology The t(8 ;2 1)(q 22;q 22 ) is found in -5% oftranslocations/inversions cases of AMl and in 10% 01 the prior acuteThis group is characterized by recurrent myeloblast ic le ukaemia with matu rationgenetic abnormalities of prognostIC signif- (M2) c ategory of the French -American-icance. The most commonty identified are British cl assification. It occurs predomi-balanced abnormalities: 1(8 ;21)(q22:q22), nantly in younger pat ients .inv( 16)(p 13. l q22) or I(16:16)(p 13 . ;q 22),1(15;17}(q22;q12) and 1(9.11 )(p22;q23) Cli nical featu res1306. 72 1, 848 , 20361 . Each 01 these Tumour manifestations , such as myeloidstructural ch romosome rearrangements sarconas. may be present at presentation . FIg. lOl /IoI/IIl myeloid IeUlaenia Wlltl .8 11XQ22:Q22creates a fusion gene encoding a chi- In such cases the initial bone marrow (BM) Bone marrow tllasts s/lowirlg abl.n:lant pUrmaeric protein that is required. but usually aspiration may show a mis leading low qtIpIasm WIlh ~deari1g em Wge~not sufficient. for leukaemogenesis 120631Many of these d isease groups have char- . number of b last cells. but should be diagnosed as AMl despite a b last per- .........ac teristic morphological and immuno- centage in the BM of <20,p henotyp ic features 1651. The categoriesof acu te mye loid leukaemia (AML) with Morphology and cytochemistry1 :2 1)(q22:q22), iov( 16 )(p 13. 1q22) or (8 The co mmon morphological features in-1(16:16)(p 13 .1;q 22 ) or l(lS;17)(q22:q 12) c lude th e presenc e of large blasts withare considered as acute reukaermas abundant basophilic cytoplasm, oftenwithout rega rd to blast cell cou nt. It is not containing nume rous azuroph ilic granulesyet c lear if all c ases with t(9; 11Xp22;q23) , and perinuclear clearing or bots . A fewt(6 ;9)(p 23 ;q34 ). inv(3 )(q2 1q26,2), t(3;3) b lasts in many cases show very large(q 21;q26 2) or t( 1;22)(p 13;q 13 ) shoul d be gra nules (pseu do-Chedrak-Hiqashi gran -c ate go rize d as AMl when the blast cell ules), sug gestin g abnormal fusion . Auer Fig. 6.02 Myeloid sarcoma Biopsy of an orbitaIlIIaSlcount is <20%. Many of the trans loca tions rods are freq uently found and appear as a fr a child w;th AML with a ~ a;21)(q22;q22). There in omare dete cted by AT-PCA whic h has a sing le long and sharp rod with tap ered eosinoph~ precursors scattered in !he preOominat1l lNs1higher sensitivity (1x 10"5) than c ytogenetic e nds; they may be de tect ed in mature poplI lation.analysis (1x 10-2 ) . Cases of therapy- related neutrophns. In addition to the large bla stAMUmyel odyspla st ic syndrom e (MD S) c ells , some smalle r bla sts, pred om inantlymay also have the balanced transloc ations in the peripheral blood (PBj, may be found. Immunop henotypeand invers ions that are d escribed in this Promyeroc vtes, myeiocytes and mature Most cases of AMl with the (8;21 )(q22;q22)section, but the se should be diagnosed neutroph ils with var iab le dy sp lasia are transloc ation d isp lay a characteristcas therapy-re lated AMUMDS with th e present in the BM. These ce lls may show imm uno phenotype with a subpopulatiooassociated g enetic abnormality noted. abnormal nuc lea r seg mentation (e.q. of blas t cells show ing hig h intensity ex- pse uoo-Pelqer-Hoet nuc lei) and/or cy to- pression of CD 34, together with HLA-DR , plas mic staining ab nor malities, including myercoeroxidase (MPO) and CD13. bJAcute myeloid leukaemia with homogeneous pink colo ured c ytoplas m in relatively weak expression of CD33j114Q, neutrophil s. Dyspl asia of othe r Cell lines, 17751. There are usually sig ns of granulo-t(8;21)(q22;q22); RUNX1· however, is uncommon. Eosinoph il precut- cyt ic differen tiation with subpopuianonsdRUNX1T1 sees are frequently increased. but they do not cells showing granulocytic rnaiuranco exhibit the cytological or cytoc hemical ab - demonstrated b y CD15 and/or COODef inition normalities charac teristic of AMl associated expression . Sometimes po pulations cIAcu te myeloid leukaemia. with t(8 ;2 1) with ab nor ma lities of c hromosome 16: blasts showing matu ration asynchrony(q22;q22); RUNX 1-RUNX7 T1 is an AMl basop hils and/or mast cells are sometimes are present (e .g . co-expressing COOtgene rally showing maturation in the neutro- present in exce ss. A monocytiC component and CD15 ). These leukaemias frequenphil lineage. is usually minimal or absent. Erythrob lasts express the lymphoid marke rs CD19 and and meg akaryocytes are morphologically PAX5, and may express cvtoptasrreICD-Ocode 9896/3 normal. Rare c ases with a BM blast per- CD79a 1996, 1155. 2236} . Some cases centage <20 occur, These should be are terminal deoxynucleotidyf transferase cl assifi ed as AMl and not as MOS. (TdT) posi tive ; however, TdT exoresscoe110 Acute rnyelord leukaemia and related p recursor neo plasms
  • 106. generally weak. C056 is expresse d in a goo d response to ch emotherapy and afraction of cases and may have adverse high com pl ete remission rate with long-prognostic significance {1231· term d isease-free surv ival when treated with high dose cytaratnne in the consoli-Genetics dation phase 1228. 8481. Some factorsThe genes for both reteroosreoc compo- appear to adversely affect prognosisnents of core bindll)Q lactor (CBF), RUNX I including C056 expression aOO the pres-(atso known as AML 1or CBFA) aOO CBFB ence of KfTmutations 1123. 16961.ere involved in rearrangements associatedWIth acute reukaemes {20631. The t(8 ;21)(Q22;q 22 ) involves the RUNXI gene, which Acute myeloid leukaemia with Fig. 6.04 Acu1e myeloid leukaemia with associatedencodes core- bi ndin g factor subunitalpha and the RUNX 1T1(ETO) gene {608, inv(16)(pI3.1q22) or inv(16Kp13.1q22). AbnonnaI eosi~ . one VIlth Large basophiliccoloured granules. aAl present1294, 17331 The RUNX1 -RUNX1T1 fu- . t(16;16)(pI3.1;q22); CBFB·sion transcri p t is consistently detected in MYH11patients with 1(8;21)(q 22;q 22) AML. The Clinical featuresCBF transcripti on factor is essential for Definition Myeloid sarco mas may be p resent atbaematopolests. and tr ansformation by Ac ute myeloid leu kaemia with inv(16) initial diagnosis or at relapse and mayRUNX 1-RUNX 1T1 likely results from tran- (p1 3.1q22) or t(16: 16)(p13,1:q22); CBFB- c onstitute the only evidence of relapse inscriptional repression of normal RUNX1 MYH11 is an AML that usually shows some patient s.target genes via abe rrant recr uitm ent of monocytic and gra nuloc ytic differentiationnuclear transcription al co- repressor com- and characteristically abnormal eosinophil Morpholog y and cytochemistryplexes. Over 70% 01pati ents show aooi- component in the BM {1258. 1393, 20631. In these cases. in addition to the usualIIQll3I chromosome abnormalities: e.q. loss morphological featu res of acute myelo-rJa sex chromosome or d el(9q ) with loss ICD-O code 9871/3 monocytic leukaemia, the 8M shows arJ 9Q22. Secondary cooperating mutations variable number of eosinophils (usually in-rJ KRAS or NRAS are common (30%) in Synonym creased. but soretrres <5%) at all stagescaedtamc CBF·associated leukaemias Acute myeloid leukaemia with abnormal 01 rretoratco without significant maturation~l. Mutations of KIT occur in 20-25% marrow-eosoconns . arrest. The mos t striking aboomantee in-01 cases (16961. volve the immature eosinophilic granules. Epidemiology mainly evident at the promyelocyte andPostulated nor mal cout erpart Either inv(1 6)(p 13.1q22) or t(16 ;16) myelocyte stages . The abnormalities areMyeloid stem cell wilh predominant reuno- (p13. 1;q22) is found in 5-8% of all cases usually not p resent at later stages ofphil differentiation. of AM L. They can occur in all age grou ps eosi nophil maturation . The eosinophilic but are found predom inantl y in younger granules are often larger than mose nor-Prognosis and predictive factors patients. mally pr esent in immature eosmocnus.Acu te myelo id leukaemia with t(8;21) p urp le-violet in colo ur, and in some cells(q22;q22) is usually associated with a are so dense that they obscure the cell 16 inv(16) • • --<> --<> • XI• I . 16 inv (16) :~:>:AFig. 1.03 Acute myeloid leukaemia with inv(16)(pt 3.1q22). A The inversion 16 results from breakage and rejoining of bands 16p13.1 and 1&;22 G-banded normal (nI) .linrTIosome 16 and irW(16) are shown. B Dual rolor ftUOfllSC6OC6 in situhybridizalion: !he 5 regll)llof CBFB is labeled in red; !he3 regionin pen Anonnal ettromosome 16 has~ 5and 3 regions ~ 10 e<lch otherresultiog in a siogle yellowOf oveOappiog IlldIgreen signals, The invefsion 16splits theCBFB locus resulting in separale red andgreensigla/$. 80Itl interphase ooIIs have one normal 16etvomosome andoneinv(16), Acu te myeloid leukaemia with recurrent genet ic abnormalities 11 1
  • 107. • morpho~y. The mature eosinophils may fusio n of the CBFB gene at 16q22 to the Acute promyelocytic leukBemia occasionally show nuc lear hyposegmen- MYH 11 ge ne at 16p 13.1 1 20061 MYH11 . lal ion . The naphthol-ASD-chloroacelale codes for a smooth muscle myosin heavy with t(15;17)(q22;qI2); esterase reaction. which is normally chain 15061. The CBFB gene codes for PML-RARA negative in eosinophils, is charactenstically the core binding factor (CBF) beta sub- faintly pos.tive in these abnormal eosmo- unit, a heterodimeric transcription tactoe Definition phils. Such a reaction is 001 seen in eoero- known to bind the enhancers of t-een Acute promyelocytic leukaemia (API. or phils 01 AML with the 1(8;21)(q22;q22). rece ptor (TCR). Cylokine genes, and other AML with t(15 ;17)(q22;q12)J is an AMLII Auer rod s may be observed in myelo- genes. The CBFB subunit heterodimerises which abnormal promyelocytes predcm- blas ts. At least 3% of the blasts show with CBFA, the gene product of RUNXl, nate. 8cttl hypergrarUaror "lypil:3" APLcnl mveioperoxioase (MPO) reac tivity. The one of the genes involved in AMl with microgranular (hypogranular) types emt monob lasts and promonocvtes usually t(8;21 )(q22;q22). Occasionally cytological show non-s peci fic esterase reactivity, features of AM l with abnormal eosropnns ICD-O code 986613 although it may be weak er than expected may be pr esent without karyotypic ev i- or even abs ent in some c ases. In ad dition d ence of a c hromosome 16 abno rmality, Synonym 10the predominant monocytic and eosino- the CBFB-MYH 11 being neverthe less AM l with 1 15;17)(q22;qt2). ( ph il compo nents, the neutroph ils in the demonstrated by molecular genetic studies 8M are usua lly sparse, with a de cr eased (1533 , 1882) By co nventional cytogenetic Epidemiology number of matu re neutrc phils . The PB is ana lys is, the inv(1 6)(p1 3,lq22l/t(16:16) Ac ute promyeloc yte leukaemia comprises not different from other cases of ac ute (p1 3 ,1;q22) is a sub tle rearra ng ement 5-8% of AMl {20 78 1. The disease can mveromonccvnc leu kaemi a; eosinoobus that may be over looked when metaphase occur at any age b ut pati ents are pre- are not usua lly increased. but an occa- pr epa rations are suboptimal. Thu s, at dom inantly adul ts in mid-life. sional case has been rep orted with ab- dia gnosis, the use 01 FISH an d RT-PeR normal and increased eosi nophils in the methods may be necessary to document Clin ical featur es PB. While the major ity of cases 0 the genetic alte ration . Secondary cytoge- Typical and rricrograrlAar API.. are lrequerty inv( l6)(p13.1Q22) have been identified as netic abnormalities occur in approximately associated with disseminated inlravasoJa having abnormal eosinophils, in some 40% of cases, with +22, +8 (10 -15% coagulation (DIG) . In microgranular API.. cases they are rare and d iffic ult to lind . each), and del(7q) or +21(-5%) most unlike typical API.., the leukocyte COlJlt IS Occasooar cases with this genetic ab- commonly observed 113901. Trisomy 22 is very high, with a rapid doubling time normality lack the eosinophilia or show fairty specific for inv( l6XPl3.lq22) patients. cxty myeloid mansatcn wilhoul a I"ro"lOCytic being very rarely detected with other pri- CCJITlX)IlE!lll or only rro-ocvtc d ifferentiation. mary aberrations in AM l. whe reas +8 is Not infrequently the blast percentage is only , commonly seen in patients with other prt- at the threshold level 0120%or oc:casionally mary aberrations. Rare cases of A ML and lower. Cases with inv( l6)(p13.1 q22) or chronic myelogenous leukaem ia with both t(16; 16):( p l3. l ;q22) and less than 20% inv(16 )(p 13 ,1q22) and t(9:22)(q34:q1 l.2) 8 M blasts should be di ag nosed as AML. have be en reported, an d this findi ng in The BM treph ine biop sy is usually hyper- ch ronic myelog enous leukaemia is usually ce llular, but may occasionally be normo- assoc iated with accelerated or blast phase ce llular. of the disease 12454 J Mutations of KIT occ ur in approximately 30% of cases 116961. Immunophenotype Most of these leukaemias are c haracte r- Postulated normal counterpart ized by a complex immunop henotype with Haemetcooienc stem cell w ith potential to the presenc e of multiple b last populations: differentiate into g ranuloc ytic and mono- immature b lasts with high CD34 and cytic lineages . CD l 17 expression and pop ulations d if- ferentiating toward s gran ulocytic (CD13, Prognosis and predictive factors CD33. CD l5. CD65. MPO positive) and Clinical studies have shown that pa tients monocytic (CD 14. CD4. CDl 1b. cone. with AMl with inv(16)(p13 .1q22) or 1(16;16) ~ CD64. CD36 and lysozyme positive) line- (p13.1;q22) achieve longer complete ages Mat urat ion async hron y is often remissions when treated with high dose B seen. Co-expression 01CD2 with myeloid cytarabine in the consolidation phase Fig. .05 Acute promyeIocybc leukaema. A ~ mark ers has been frequently documented 1848, 15301. j-owever. older patients have ~ type n bone marrow smear. Theft we IMi abnormal prornyelocyles wilhITIense amq:hIc,..... but It is not specmc for this di agnosis. d ec rea sed survival and tho se with KIT lam. Sewr1lI ollhe promyeIocyles oontaillUl-.all mutat ion s have a higher risk of relapse Auef rods(Iaggot oeIs). B M~ vWrt. 11 Pt- Genetics and worse survival 1546. 16961. Patients ripheral bloocI smear. There are several abnclmll The inv( 16)( p 13, 1q22) foun d in the vas t with +22 as a secondary abnormality have promyelocy!es Mthlobl,Jlaled. almostc:eretlnbm ru:Il major ity of this subtype and the less com- bee n reported to have improved ou tcom e The cytoplasm coola numerous small alI.tllPl* ins mon t(16; 16)(p13, 1:q22) both resu lt in the 11390. 196 21 . granules: other ~Is appear sparsely ganlMr. 112 Acute mye loid leukaemia and related precu rsor neoplasms
  • 108. nl 15 d .~15 ) 15 17 II 1(15 ;17XQ22;Q12) A ~ U16 AcuIe prorll)8locybc IeuilaenU WIIh 1(15;11Mq22;q12), A The Dlslocabon 15;11 t&SUts from br9akage ald r-.nion of bands 15q22 ald 11q12. G-bMded normallnl) 15 111 17 dY::Jnc:lsanes (Ieft.l aldthe derivatNe ldetl 151n:l11 reslAng from ee IransIocation are sIlOWlI on hi fil1C. BOuaIlDorlunscence" sill hybtidiZ.alion M1h probes Pf.C. l~ iIllll RARA(17ql2) derroostrate the presence of a Pl.UWtA.lusion ~ from the 15;11 transIoca1ol Eactlof hi fwee IlBphase eels has one sep;nte red (PK) . J9W. (WII sepataIe ween (RARA) sigIaI, In:l one dOw or~ ~greet1 si!r.aI ronsislenl..,1Il1tle pttl5etIC8 of a PMJRARA gene Iusioo. IbphoIogy and cytochemistry The apparent hypogranular cytoplasm weakly expressed 11654. 1678} and CD64 The nuclear size and shape in the aboor- relates to the submicroscopic size of the expression is common. In cases with rrel promyelocytes of hypergranular APL azurophilic granules. This may cause c0n- microgranular morphology or cera Iran. ere irregular and greatly variable; they are fusion with acute monocytic leukaemia on scr ipt of the PML-RARA fusion gene there ::tten kidney-shaped or bilobed . The cyto- Romanowsky stained smears; however, a is frequent expression of CD34 and C02, plasm is marked by densely-packed or small number of the abnormal promyelo- at least on a fraction of cells 16531. Ap - even coalescent large granules, staining cvtes showing clearly visible granules proximately 20% of APl cases express :Yight pink, red or purple in Romanowsky and/or bundles of A uer rods (faggot cells) C056. which has been associated with a stains. The cytoplasmic granules may be can be identified in many cases. The worse outcome 16901· Using enrourocvto- solarge andior numerous that they totally leukoc yte count is frequently markedly Chemis try, antibodies against the PML rescore the nuclear cytoplasmic margin . elevated in the microgranular variant of gene product show a characteristic nu- In some cells. the cytoplasm is filled with APL with numerous abnormal mcroqran- clear multigranular pattern with nucleolar Ire dust-like granules. Characteristic cells ular promy elocytes in con trast to typical exclusion, in contrast to the speckled rela- containing bundles of Auer rods ("faggot APL. The MPO reaction is strongly pos itive tively large nuclear bodies seen in normal cells") randomly dis tributed in the cyto- contrasting w ith the wea k or negative reac- oromverocvtes or blas ts from other types plasm are present in most cases, Myelo- tion in monocytes. Abnormal promveocytes of AML (6621. blasts with sing le Auer rod s may also be w ith deep ly baso ph ilic cy toplasm have Observed, A uer rod s in hyper gr anu lar been de sc ribe d ma inly in the rela pse Genetic s APL are usually large r than in other types phase in patients who have be en p revi- In ad d ition to its thera pe utic imp act, the rJ. AML and they may have a c haracteristic ou sly treated w it h al l-tran s rettnoic acid sensi tivity of APL cells to ATRA has led to rrorpholog y at the ultras truct ural leve l (ATRA), The 8M biop sy is usual ly hyper- the d iscovery that the retinoic acid receptor .vith a hexagonal arrangement of tubular cel lular, The abnormal promyelocyt es have alpha (RARA) gene on 17q12 fuses with a structures with a specific period ici ty of relatively abu ndant c ytoplasm with nume r- nuclear regulatory fac tor gene on 15q22 aeoroxrnaterv 250 mm in contrast to the ous g ranul es: occasionally Aue r rods may 6-20 lamina r periodicity of Auer rods in be identified in well-prepared specimens. erertypes of AML. The MPO reaction is The nuclei are freq uently convoluted always strongly positive in all the exaernc oromyeiocvtes . with the reac- Immunophenotype tion product covering the entire cytoplasm Acute p rom vetoc vtrc leukaemia with the l"Id often the nucleus . The non -specific t( 15 ;17)(q22;q 12) (hypergranular or "typ- esterase reaction is weakly positive in ao- ical" variant) is characterized by low ;>rQximately 25% of cases. Only occa- expression or absence of HLA·DR. CD34.SJOnaI obvious leukaemic prooweiocvtes leukocyte integrins CD11a, CD 11bandmay be observed in the PB. CD18. a homogeneous, bright expressionCases of rracrcqranurar (hypogranular) of CD33, and heterogeneous expressionA.PI. arecharacterized by distinct morpho- of CD13_ Many cases show expression Fig. 1.07 Aone promyeIocytic Ieukaema. Bone IIIiWTtIWQJicaI features such as apparent paucity of CD117, although sometimes weak . biopsy. Abnormal prorrt)eIotyIe wilIl abl.ndalll hyper.CJ absence of granules. and predomi- The granulocytic differentiation markers gran,Aated cytlpIasm. Thenudei are genefaIylWId tIIlafltly bilobed nuclear shape 18111. C015 and COO5 are negative Of only oval. SewlraI of !tie nudei llfll lfregU;w and I!YagrIaled Acute myeloid leukaemia With reconenr genetic ebroerrautes 113
  • 109. the p rognosti c signific ance of FLT3-JTO present in 9-12% of paed iatric and 2%rJ mutations in this di sease remains unc lear adult AML 1 306 . 721 1. /690 , 1199 1. Cunicalteatures Variant RARA transl ocations Patients may pr esent with d isseminaled in acut e leukaem ia intravascular coagulation. They mayhave A sub set of c ases. often with mor pho- extramedullary myeloid (monocytic) serco logical fealures resembling acute ~ mas and/or tissue infiltration (gingiva, skn~ cvtc leukaemia. show variant nensocetcos involv ing RARA . These variant fusion part- Morphology and cylochem;SbyFig.6.08 PM!. anI1body n aaM promyeIocybc IeukaenIa ners inc lud e ZB TB 16 (previously known There is a strong association betweenshowing a etlaractetistic Ill.Ideaf mufbgrnular paltem as pr omv eiocvtrc leukaemia zinc finger acute monocytic and myelomooocytlcMIll ru:leoIar exclusion. gene or PLZF) at l 1q23; the nuclear ma- leukaemias and t(9; 11)(p22;q23). altho.ql trix assoc iated g ene (NUMA 1) at l 1q 13; occasionally the t(9 ;11) is detected il At.( the nuc leophosmin gene (NPM1)at5q35 with Of without maturation. MonobIaSlS(o ronvelocvnc leukaemia Of PML gene) and STATSB at 17q l 1.2 124881 . and promonocytes typically predominalegiving rise to a PML-RARA fusion gene Some c ases with vari ant transiocanons Monoblasts are large cells . with abt.r1ci<rfproduCII506, 529 . 14521. Rare cases 01 we re initially reported as having APL cytoplasm which can be moderately to.,.APt. lacking the classic t(15:17)(q22;q 12) morphology 119141. However. the t(l l ;l7) tensely basophilic and may shcwt oseccoon routine cytoqenenc studies have been (q23;Q12); ZBTB16-RARA subgroup shc1ws pod lormabon. Scattered fine azurophilo:described with complex variant transio- some morphological d ifferenc es with a granules and vacuoles may be presetcations involving both chromosomes 15 predominance of cells with reg ular nuclei, The rrooobasts usually have round BJCIliand 17 with an additional chromosome Of many granules . usual absence ot Auer With del icate lacy chromatin, and one f1with submicroscopic insertion of RARA rod s. an increased number of Pelg eroid more large prominen t nucleoli. Prorcoointo PML leading to the expression of the neutroph ils and strong MPO activity {19141 . cvtes have a more irregular and delicat~PML -RAR4 transcript ; these latter cases are The initial cases of APL associated With convoluted nuclear configuration; the evtrconsidered as cryptic Of masked t(15 ;17) t(5 ;17)(q35 ;q1 2) had a p redom inant pop- plasm is usually less basop hilic ana(Q22;q12) /6471. Mor pho log ic al analysis ulation of hypergran ular promyeiocvtes sometimes more obviously granulated,shows no major d ifferences be tween the and a minor population of hypogranular with occasional large azurophilic grarUe!t( 15;17)(q 22 ;q 12) positive group and the promyelocytes; Auer rods were not oennteo and vacuoles. Monoblasts and proro-oPML -RA RA positive p atients wi thout by ligh t m ic rosc op y 1 6 1. Some acute 47 cvtes usually show strong positive flCJlt( 15; 17)(q22;Q12) , Secondary cytogenetic promyelocytic leukaemia variants. incl ud - specific esterase reactions. The rrcocoassabnormalities are noted in - 40% of c ases . ing t( 11; 17)(q 23;q1 2) w ith ZBTB16-RARA ofte n lack MPO reactivity.with +8 being the mos t frequen t (10- 15%). and cases wit h S T AT5B· RA RA fusion s areMutatio ns involving FLT3, including inter- res istant to ATAA 114521 APL with the , Immu nophenotypenal tand em duplic ation (ITO) and tyrosine t(5 :17)(q35;q 12 ) appears to resp on d to Cases 01 AML with the t(9: 11)(p22;q23) ir1kinase doma in mutations (TKO) oc cur in ATRA {1452]. c hild ren are associated with strong34-45% of A PL. FLT3-l TO mutation s are Cases with these va riant transroc atlons exp ression 0 1 CD33, CD65 , CD4 andmo st co mmon and a re associated with a should be d iagn osed as AML w ith a HLA-DA, while exp ression at CD 13, CD34high er white b lood ce ll co unt. mlcrocran- va riant RARA transloc ation. and CD 14 is usually low /491 1 .urar b last ce ll mo rph olog y and involve- Most AML c ases w ith 11q23 abnormalitiesment of the bcr3 b reakp oint at PML 1318, express the NG2 homologue (encoded by747 ,1 199). Acute myeloid leukaemIa with CSPG4j, a c hond roitin sulfate molecule reacting with the Mab 7.1124561 MostacU: .Postulated normal counterpart t(9;II)(p22;q23); MLLT3·MLL AM l case s w ith 11q 23 ab normalitiesMyeloid stem ce ll with potential to d iffer- exp ress some marke rs 01 monocacent iate to granulocytic lineage. Definition differentiation including CD14, CD4, COlle Ac ute myeloid leuk aemia with t(9; 11) CO l lc. CD64. CD36 and lysozyme, v.tIireProg nosis and pred ictive fac tors (p22;q23): MLLT3-MLL is usually associ- variable expression of imma ture markersAc ute promyetocyttc leukaemi a ha s a ated w ith monocytic featu res . suc h as CD34 and CD1 17 and of CD56p artic ular sensi tivi ty to treat ment w ith has been reported {154 11.ATRA. which acts as a dilferentiating ag ent ICD-O code 9897/31342. 2 152/. The prognosis in APt.. treat ed Geneticsoptimally With ATRA and an anlhrac ycl ine Synonym Molec ular studies have iden tified a t1t.rnaIis more favou rab le than lor any other AML Ac ute myeloid leukaem ia . 11q23 abnor- homologue of the Drosophila trithoraxcytogenetic subtype. and cases of relapsed ma lities. gene design ated MLL (HRX), that resultsor refractory APt. show a generally good in a fusion gene in translocations invo/Vllgrespo nse with arsenic tr ioxide th era py Ep;demk>logy 11q231 1141 The MLL p rotein is a histl)1!! .1607.6851. Expression of CD56 is associ - The t(9;11)(p22;q23) may occur at any mettwnransterase that assembles in pro.ated with a less faVlJU(able prognosis while age. but is morecomnor I in child ren. being tein complexes tha t reg ulate g ene Iran.114 Acute myeloid leukaemia and related precursor neoplasms
  • 110. scription via ctuomato remodel ing. The~9:11)(p22:Q23) involving MLLT3 (AF9 ) istoe most common MLL translocation inAML and appears to represent a distinctenhty. Secondary cytogenetic abnormalitiesare common with t(9:11) (p22:Q23). with+8 most commonly observed, but do notappear to influence survival [306, 15311.Postulated normal cou nterpart Baaenaiopoeuc stem cell with multiJineage Fig. 6.09 AML (monoblaslic) WIth t(9;1Xp22;q23). Bone marrow smears A 5evefallllOllllblasts. some WIth veryootennar. allurl<Ia1l cytoplasm and h myelopeloxidase,..1iYe azurophilic granules are present B Non-speciflc esterllse reacbon showing I1lensely poslIiYe IrOlOblasts,Prognosis and pred ictive factorsAcute myeloid leukaemia with the. 9:11XP22;Q23) has an intermediate sur- ".....aI and one that is supefior to AML withe:tner l1Q23 translocations 11531. 18911.Cases with the t(9: 11) and <20% blastsIIIJSt be monitored closely fOf develop-ment of more definite evidence of AML. fi1riant MLL translocations in acute leukaemia C>ief 80 different translocalions involving MLL are now described in adult and .. Fig. 6.0 Mt. (1TIOII:ltyIic) Mlh 1(9;11)(p22;q23}. Bone tJWI(M ~ A ThenlarelilMlt8llfOIObIasts and ~ with very pale cytor*lsm containing numerous fine anrophiic ~_ The promonocyles have delicate rudear lolds. paediatric acute leukaemia, with over 50 B Noo-speci1ic esterase SaII"I_ The pn::monocytes are intensely reactive. eensiccato n partner genes now cnarac- lenzed 11 470. 20081. rrensiccetcoe involv- ing MLLT2(AF4). resuitmq predominantly n acute lymphoblastic leukaemia (ALL). abnormalities associated with prior ther- Clinical features end MLLT3(AF9). resuhing predominan tly apy or myelodysplasia. such as t(2; 11) Acute myeloid leukaemia with t(6:9) n AML, are the most common. Other MLL (p2 1;q23) or t( 11:16)(Q23:p 13.3), should (p23 ;Q34) usually presents with anaemia eensccauons that commonly result in AML be diagnosed as therapy- related AML or and thrombocytopenia, and often with rcuoe the MLLT1(ENL). MLLTIO (AF1O), AMl with myelodysplasia- related changes pancytopenia, In adults, the presen ting MLLT4 (AF6) and ELL as partner genes, (See Cha pter on therapy-related myeloid white blood cell count is gener ally lower Other than the ML L-ELL fusion resulting neoplasms), than other AML types with a median white Irom the t(1 1:19)(q23:p13,1), which is blood cell count of 12x1()9/L 120351, res often associated with only AML, these fusions occ ur pr edom inantly in Acute myeloid leukaemia with Morphology and cytoche mistry A L, but may be seen in ALL as well. Up M The BM blasts of AML with t(6:9XP23:q34) 10 one third of MLL transiocauons in AML t(6;9)(p23;q34); DEK-NUP214 may have morphologic and cytochemical ee not detectable on co nventional kary- features of any FAB subtype of AML other otype analysis , and FISH or other Definition than acu te promyelocytic leukaemia and molecular stud ies may be necessary to Acu te myeloid leukaemia with the 1 :9) (6 ac ute megakaryoblas tic leukaemia. withdentify these variant translocations 120081. (p23:q34); DEK-NUP214 is an AML with AML with maturation and acute mvero-AML with these fusions usually have or without monocytic features that is often monocytic leukaemia the most commonmyelomonocytic or monoblastic rro rpno- associated with basophilia and multilin- 128, 1676,20351_ Auer rods are present inbgic and immunophenotypic features eage dysplasia {17 14, 20351 . approximate ly one third of cases, BlastsWhile in the p ast all of these transloca- are myeloperoxidase positive and may beli:lns were encompassed by the category ICD-Ocode positive or nega tive for non-specific es-rj AML with 11q23 abnormalities. the di- The provisional code proposed for the terase . Therefore , there are no featuresagnosis should now specify the specific fourth edition of IGO-D is 986513. specific to the blast cell population in thisabnormality and should be limited to entity Marrow and PB basophilia. definedcases with 11q23 balanced translocations Epidemiology as >2% , is generally uncommon in AMLfIoOIving MLL. For example. a case of The t(6:9Xp23;q34) is detected in 0.7-1 .8% but is seen in 44-62% of cases of AML withAMl with an MLL-ENL fusion would be of AML, and occurs in both children and t(6;9)(p23:q34). In addition. most casesdl8gnosed as acute myeloid leukaemia adul ts with a median age 01 13 years in """ evidence oIgarL<ocybc and _dh ~11 ,19)(q23;p13 .3): MLL-ENL. childhood and 35 years in adults 1306. dysplasia. with megakaryocytic dysplasia40Jte myeloid leukaemia with cytogenetic 2035,20361. possibly less common. Ring siderooiaere Acute myeloid leukaemia wIth recurrent genetic eoocereetes 115
  • 111. • a re presen t in a subset of cases, The per- Postulated normal count erpart Morphology and cytochemistry centage of 8M blasts is variable. and Haematopoietic stem cell with mullilineage Periphe ral bloo d chan ges may include some cases may present wi th less than potential. hypog ranular neutrophils with a pseudo- 20% bl asts. Petcer-Hcet anomaly, with or without Prognos is and predictive factors assoc iated peripheral blasts. Red eel Immunophenotype Acute myeloid leukaemia with t(6:9) abnormalities are usually mild withOOt The blasts have a non-specific myeloid (p23;q34) in both ad ults and children has teardrop cells. Giant and hypogranulat immunophenolype with consistent ex- a generally poor prognosis. similar to other platelets are common and bare mega- pression of myeloperoxidase. CD13,CD33. AMl with unfavourable cytogenetic ab- karyocyte nuclei may be present 12251. The C038 and HLA-DA 128, 1676,20351 . Most norm alities . Elevated white blood cell 8M blasts of AML with inv(3)(q2 1q26.2l cr cases also express CDl17. CD34 and counts are most predictive of shorter t(3 :3) (q2 1:q26.2) may have morphologic C0 15 while a subset 01 cases express the overall survival and increased 8M blasts and cytochemical features of any FAa monocyte-associated marker CD64 and are assoc iated with shorter disease-free SUbtype of AML other than acute promyeIlr approximately hall are terminal oeoxv- survival. Based on limited data. allogeneic cytic leukaemia with acute myebd oodeotidy1 transferase (TefT) positive . Other stem cell transp lantation may be associ- Ieukaertia without maturation. acute myeIo- Iymp/loid antigen expression is UllCOlTITlOl1 . ated with better overall survival compared monocytic leukaemia and acute mega. to patients with no stem cen vansptanta- karyobIastic leukaemia morphologies rn:lSl Gene tics too 12035I·Cases with t(6;9XP23:Q34) and cornrnon 1715. 19831. A subset of cases The 1(6:9)(p23:q34) results in a fusion 01 <20% blasts must be monitored closely has less than 20% blast cens at the tiTle DEK on chromosome 6 with NUP214 (CAN) for development of more definite evidence of diagnosis. including cases with fsallles on chromosome 9. The resulting nocieo- of AML. of chronic myelornonocytic leukaemia porin fusion protein ac ts as an aberrant Multihneage dysplasia of non-blast eel transcription factor as well as altering nu- BM elements is a frequent finding WII/1 clear transport by binding to soluble trans- Acute myeloid leukaemia atypical megakaryocytes most cQlTllTlCll port factors 119491. The 1(6:9) is the sole 1715. 1054. 19831. Megakaryocytes may clonal karyotypic abnormality in the vast with inv(3)(q21q26.2) or be normal or increased in number WI majori ty of cases, but some patients will /(3;3)(q2/;q26.2); RPN/·EVIt many small «30 IJm) monoIobed a have the t(6:9)(p23:q34) in association with bilobed forms. but other dysplastic mega. a complex karyotype 120351. FLT3-lTO Definition karsocvtc forms may also occur. Dysplasia mutations are very common in AMl with Acute myeloid leukaemia with inv(3) of maturing erythroid cells and neutroptws t(6;9)(p23;q34) occurring in 69% of pae- (021026.2) " 1(3;3Xo21;q26.2); (RPrvI-EVII) is also corrrnon . Marrow eosooonss. teso diatric cases and 78% of adult cases is an AML that may present de novo or phils and/or mast cells may be increased 11676. 20351 Fl.T3-TKO mutations appear . arise from a prior MOS. It is often associ- The BM biopsy shows increased sma to be uncommon in this entity. ated with normal or elevate d PB platelet hyr:x>lobated megakaryocytes. Bone marnJo! coun ts and has increased atyp ical BM cellularity is variable with some cases pre- meoakarvcc vtes with mono- or bi-lobated senting as hypoc ellular AML Marrow nuclei and assoc iated multil ineage dys- fibrosis is variable. plasia (225, 1983,2 131). Immunophenotype ICO-O code Immunophenotypic studies of AML with The provisional code propo sed for the inv(3)(q21q26.2) or t(3:3}(q21:q26.2) ar e fourth edition of ICD-O is 986913. limited. The blast cells generally express C0 13. C033. HLA-OR. CD34 and C03 S Epidemiology Blast cells of some cases also abe rranf Acute myeloid leukaemia with inv(3) express C07 and a subset may express (q21q26.2) or t(3:3)(q21;q26.2) represents meg akaryocytic markers such as CQ4t 1- 2% of all AML 1 306 . 20361. It occurs and C06 1. Abe rrant expr ession of lym. most commonly in adults with no sex photo markers other than C07 appears predilect ion. uncommon [20041. Clinical features Genetics Patients most co mmonly present with A variety of abnoemauties of the long arm anaemia and a normal preteret count . of chromosome 3 occur in myeloid rnalo(t although marked thrombocythaemia nances. with inv(3)(q21q26.2) and t(3:31 occurs in 7-22% of patients 1845.19831. (q21 ;q26.2) being the most common. The Patients may present de novo or have a abnormalities involve the oncogene EVIl prior MOS. A subset of patients present at 3q26.2 . or its longer form MOS1 -EV! Fig.S." AML. with t(6:9)(p23:Q3-t). The blasts are with hepalosptencmegaty. but "",,",,dero- and RPN7 at 3Q21 APN1 may act as <WI adn ed with dyspIastlc erythroid precursors and ... pathy is UllCOI llllOlI11983. 2C04, 21891. enhancer of EVIl expression resulting scallered ~ (centre. 9ll). increased cell proliferation , and impaireo 116 Acute myelOid leukaemia and related orecursoe neoplasms
  • 112. cell differentia.lion: it induces naen etooor- ICD-O codeeticcell transformati on ( 1236, 1609, 21251 . The p rovisional cod e prop o sed fo r theOther cytog enetic aberrations involving fourth edition of ICD-D is 991 1/3,3q26.2, such as t(3:2 1)(q26.2:q 22) res-~tting in an EVI1-RUNX 1 fusion and usu- Epidemiologyally seen in therapy-related disease, are The t(1; 22)( p13:q 13) is an uncommonnot included in this disease ca tegory. abnormality in A Ml, repr esenting < 1% ofSecondary karyoty pic a bnormalities are all c ases. It most commonty occurs incommon with inv(3)(q21 q26.2) and t(3;3) infants without Down syn d rome, with a(Q21;q26.2) with monosomy 7 most com- female pred ominance . -mon, occu rring in approximately half of Fig. 6.12 AML WIth irlV(J)(Q21 q26.2). Bone marrow-cases, followed by 5q deletions and com- Clinical features aspAte wrlhincreased blasts and atypica, rncnJIobaIed"" ...",.",..1 1963/. These abroonalrties Acute mye lo id leukaemia with t( 1;22 )may precede the development of the (p13;q13) is a de novo AMl restricted to3q262 abnormality 116091. inf ants and young chi ldren (3 yea rs orPatents with AMl with inv(3)(q21q26.2) less) with most cases occurring in the first marker CD42 (g lycoprotein Ib) is less fre-««3:3Xq2 1;q26.2) show overexpression 6 months of life (median, 4 months). The quently present. The myeloid~associatedd EV/1 and GATA2 bulthese fIndings do , last rnajonty of cases present with markers CD 13 and CD33 may be positive.ro appear to be specific for the genetic marked organomegaly, especially hepato- CD34 , the pan-leukocyte marker C045,aonormality 11236,16091 . splenomegaly. Patients alsohaveanaemia, and HLA-DA are often negative; CD36 isP atients with chronic myelogenous leu- and usually have throm bocytope nia and Characteristically pos itive . Blasts are neg--.aemia may acquire inv(3)(q21q26.2) or a moderat ely eleva ted white blood cell ative With MPO antibodies. lymphoid(3:3kq21;q26.2), and such a finding usually count. markers and terminal deoxynucleotidylportends accelera ted or blast pha se of trans ferase (TdT) are not expressed, Cy-!heir disease , Cases with both t(9 :22) Morphology and cytochemistry top lasmic exp ression of CD4 1 or COBt is(Q34;q11.2) and inv(3 )(q 21q 26.2) or t(3;3 ) The PB and BM blasts 01AML with t( 1;22 ) more specific and sensitive than surface(q21;q26.2) are best considered as ag - (p13;q 13) are similar to those of acute staining ; the higher specificity is due tog-essive phases 0 1 ch ronic myelogenous megakaryoblastic leukaemia of AM l, NOS. possible adherence of p late lets to b lastleukaemia. rather than AMl with inv(3) Small and large megakaryo blasts may be cells in othe r types of AML, which may be(q2tq26.2) or t(3;3)( q2 1;q26.2). p resent and they may be admixed with misin terpreted as positive staining by flow more mor ph olo gically und iffe rent iated cvtometrvPosllJlated normal counterpart b last ce lls with a high nuclear-cytoplasmictiaematopoietic stem cell with multilineage ratio resembling ivmorobrasts. The mega- GeneticsPOtential. karvobtasts are usually of medium 1 large 0 Patients sho uld have karyotypic evidence size ( 12- 18 urn) with a round, sligh tly ir- of t(1 ;22)(p1 3 ;q13) or molecul ar geneticPrognosis and predictive factors requrar Of indented nucleus with fine retic- evidence of a RBMI5-MKL 1fusion, In mostAML with inv{3)(q 2 1q26 .2) or t(3;3) ular ch romatin and one to three nucl eoli. cases, t( 1:22)(p 13;q 13) occurs as the sole(q21:q26.2) is an aggressive di sease with The cytopl asm is ba sophilic , often ag ran- karyotyp ic ab normality, This trans locat ionsort survival 171 5 , 1834, 1983 1 Two pa- . ular, and may show d istinct ble b s o r resu lts in a fusion of RNA-b inding motifti nts with AMl with inv(3)(q2 1q 26.2) were e pseudopod formati on. Mic romeg akaryo- protem-rs (RBM1S) (also known as OTT)reported to show a response to a rsen ic cvtes are common , but d yspl astic fea- and megakaryoc yte Ieukaemia- t (MKL 1 )trioxide with thalidomid e, w ith one act u ev- tures of gra nu locytic and eryth roid c ells (also known as MAL) (1352 ). RBMIS en-i19 complete rem ission 11 824 j , Cas es are not usually p resent The 8 M biopsy is co des RNA recognition motifs and aspenlI,ttl inv(3)(q2 1q2 6 ,2) or t(3:3)(q 21;q2 6 .2) usually normocellular to hyperce llular with par alog and ortholog C-terminal (SPOC)and <20% bla sts must be mo nitore d retic ulin and co llage nou s fib rosis usually domain , whi le MKL 1 encodes a DNA-C lOSely for development of more d efinite presen t. Cases may show a stromal pat- bin d ing motif involved in chromatin or-evidence of AMl. tern o f BM infiltration mimicking a meta- ganization. The fusion gene may modul ate static tumour 1 5, 341 1 Cy toc hemical 20 . chromatin orga nization . HD X-ind uced dif- stains for Sudan black B (SBB) and MPO ferenti ation and extrace llular sig nalingAcute myeloid leukaemia are cons istently negative in the megakaryo- pathways 11461}. b lasts. A subset of cases will have less(megakaryoblast/c) with then 20% BM bla sts. but a low blast cell Postu lated normal counterpart~ 1;22)(p I 3;q I 3); RBMI5-MKL 1 count due to difficu lties aspira ting BM sec- Myeloid stem cell with predominant mega- on dary to fibrosis sho uld be excluded . karyocytic d ifferentiation .Defi1ition, cute myeloid leukaemia with t( 1;22) IrrmJnophenotype Prognosis and predictive factors(p13;q 13); RBM15-MKL 1 is an AMl gen- The megakaryoblasts express one or more Although early report s suggested a poorEJaJy showing maturation in the mega- of the platelet g lycoproteins: CD41 (glyco- prognosis for AM l with t( 1;22)(p13; q 13)karyocyte lineage. protein lIb/l lla ), and/or COO1 (glycoprotein 1205.34 11. more recent studies have found ilia). The more matu re platelet-associated the patients to respond well to intensive Acute myelotd leukaemia WIth recurrent genetic abnormalities 117
  • 113. AML chemothe rapy with long disease-free kinase domain (TKO) (20-35%). vVhile FLT3 6-15% of all AML. NPM 1 mu tations aresurvival 16201. Cases wi th the t(1;22) mutations may occur in association with typically heterozygous and the leukaema(p13;Q 13) an d <20% blasts on aspirate recurrent cytogenetic abnormalities, such cells retain a wild-type allele [6671. Theysmears should be correlated withthe biopsy as t(6;9XP23 ;Q34) and t( 15;17){Q22;Q12), usually oc cur at axon 12 01 the NPMrto excjooe 8M fibrosis as a cause of a they may also occur with other so-called gene 16661 but rarely involve exon 9 a t1falsely low b last cell count. 11 this is ex- cooperating mutations. FLT3-HOmul ations n 11 About 40 mutation variants ha...ec luded, these pat ients must be monitor ed are associated with an adve rse outcome, been described 16671. the most COf1Yl"Olclosely for d evelopment of more definite b ut the sig nificance of the less common being mutation A, a TCTG tenanucreotoaevide nce of AML, such as the pres enc e FLT3- TKO mutations remains c ontroversial dupl ica tio n at posi tions 956 to 959, whichof extramec ouary di sea se or myeloid sar- 1117, 1447,2396 1 Detection of FLT3-lTO . accounts lor 70-80% of ad ult AML wltnco ma, is important be cause th e prognosis of NPMI mut ation , Ind ep end ent of type, most cytogeneti cally normal AML subtypes NPM 1 mutat ions g enerate common eje- correlates with the presence or ab sence atrons at the C-terminus of NPM t of this muta tio n KIT, loca ted at 4Q11-12, leukaemic mutants, i.e. re plac ement o!AML with gene mutations is a mem be r of the type III tyrosine kinase tryp tophan (s) at position 288 and 290MldIn add ition to translocations and inversions, family and encodes a 145-kO transmem- cre ation of a nuclear export signal (NE Slspecific gene mutations also occur in AML. brane glycoprotein. Gain-of-function muta- motif, which mediates aberrant localiza-They include frequent mu tations of fms- tions of KIT occur in a variety of d iseases, tion of NPM to the cytoplasm 16671.related tyros ine kinase 3 (FLT3), nucleo- including g astrointestinal stromal tumours. CEBPA (CCAAT/enhancer-bind ing pro.phosmin (NPM 1) and . less corrmonly, germ cel l tumours , mastocytosis and AML teo-c) mutations occur only in AMl <WCmutations of the CEBPA gene (encoding Mutations of KI Thave been shown to have are usually baneic mutations . The normalthe CCAAT/enhancer bi nding protein -c). prog nostic signifICance among AML with ge ne encodes a transcription factor Ill-KIT, MLL. WT1 , NRAS and KRAS. Alone or t(8;2 1)(Q22 ;Q22) and inv( 16Xp13.1 Q22)1 volved in control 01 proli feration and dd·in com bination, mutations of FLT3, NPMI t(16;16)( p 13.1;Q22), in which mey are as- ferent iatio n of myeloi d p roge nitors. Whieand CEBPA have been reported in patients soci ated with a poo r prognosis 11696 1 . mutations may occ ur throughout the wholewith AML with a normal karyotype where These KITmutations most common ly occur gene sequen ce , tw o general c ategoriesthey have prognostic significance in the within exoo 8 and 17. To date, WT1 rrotat cos of mutat ion occur: out-of-frame insertionsco nte xt of most cu rrent therapies . al- have been shown to co nfer a poor prog - and deletions in the N·term inal regioo artthoug h they may be seen in pat ients with nosis in AML patients with a rormat karyo- in-f rame insertio ns and de let ions in tleab normal karyotypes as well 115321 , type 11 696A I, but there is less compelling C-terminal reg ion. Mutations of NPM I ereFLT3, loc ated at 13Q1 2, encodes a tyro- evi de nce of p rognostic significance for CEBPA are freq uently observed in At.lsine kinase rec ep tor that is involved in the less freq uent mutations of MLL, NRAS with a normal karyotype an d , in the ab-haematopoietic stem cell differentiation and KRAS . Molecular studies have shown sence of FLT3-lTO, are associated wmaand proliferation. FLT3 is expressed on tMtthe MLL gene is rea rrang ed more fre- favourable prognosis 1216, 602 , 19711these progenitor cells as w ell as on the Quently than is revea led by conventional 2198 ,23311. In view of the freque ncy :;b last cells in most cases of AML. FLT3 cytogenetic studies. A partial tand em du- Ihese mutations. the ir prognostic sigM-mutations may occur with any AML type p lic ation of MLL has been reported in cance. and their association with certan(20-40% of all cases) and in MOS, but 5- 10% of ad ults Wi th a norma l kary otype morpho logic and clinical features , it hasa re mo st com mon in AML with 1 ;9) (6 [313,6031 and in patients with isolated tri- bee n sug gested that they may ident~(p23;q34 ), acute promy elocytic leukaemi a som y 11[3141. Its adv erse prog nostic sig- uniqu e subse ts of AML. Therefore, tIWand AML with a norm al karyotype 11184, nificance in patients with a normal karyotype new provision al entities, AML with mutated2035 1, The two primary typ es of FLT3 mu- is reported to be e liminated in pati ent s NPM 1 and AML with mutated CEBP are Atations a re intern al tandem duplications(FLT3-ITO) within the lu xtamemb rane do- rec eiv ing an auto logous stem ce ll tran s- p lant in first rem ission 123951. proposed. These have been giv en provi- sio nal status bec ause they have beer " E rema in (75 - 80%) and mutations affecting NPM1 mutations occur in about one third on ly rec ently described and more sfudt pcodons 835 or 836 01 the second tyrosine 01 adul t AML an d CEBPA mutations in is requi red to confirm these categories as118 Acute myeloid leukaerTlla and related precursor neoplasms
  • 114. Tillie &.01 Moleculaf geneticalteratioos allectlrtg dir1ical outcome of AML patients in specific qtogeoeUc groups. Geoetics Cytogenatiu Prognosticslgnillcance KiT mutabon$ t(8:21)(q22;q22) OFS andRFS Signlfocann~~""" -:",,~uenls ~~ Wlth KITmutatons (especially ecse ill 8loo17) lXIIf4)8red Mtt1 wiId-~ KlTpalients {233A., 2Q09A, CIRandRI Slgoificantly higher fof peteots wilh KITmutaloons compared Wlth patients with wild.fype KIT{310A, 1696} EfS signlf!canny shorter forpabents with KITmutatons (especialy eese n e.oo 17) ~red IIIilh pall8/1ts with w~ KIT(233A. 1969Aj OS si!1liflCalltly shortef Itlr patents WIth KITmuta!lorls (espec:iaIyIhOs8 ill elOfl 17)compared wrltJ pabents wr01 wiId-4ype KlT{233A.. 31QA. 1969A. 2009A} No Slgf1fflcanl dllJerence 111 0$ bereeen patients IIIilh -" wilhOul KITmutatl(lllS {1696} <IT_ ilw(16)(p131q22)1 RRIIIOfSe lor patients wrltJ KlTmutatioos 111 el M 8 COIf4lilred WIlt1 patients IIIl wid-type KrTf33Ml t(16.16)(p13,1;q22) CIR hIglMlI and OS /IIOIWfor pabents WIth KIT rrotations 11 elOfll1 c:unpared wr01 PI1ients with wid-typeKIT{1696} No Sigr*ant dillereooe in EfS , RI, RFS and OS between pabentS withand Mlhoul KJTrnuIatols (2~ 31 0A) FiJ><TD Normar CRa and DFS ~ shor1erfor pabenl$ WIth Fl.T3-lTD comparedwith palienls IIIClOlIl A.TJ.lTD {193A., 216 736A 2394A) . EfS SiglWanty sIo18r lor patents WIth fLT3-fTO comperedwotll palienl$ IlIltIloIA A.TJ.lTD (2338) OS~, sIlcrterlor patlents wotll A.T3-ITO c:unpared withpalients wrlholA FLTJ.lTD {193A. 216 736Ai . No SIgIificart dIIetence in OS b8tween palietn WI!! ald witlCUfLT3-lTD(2338, ~ ......... . RJJ.m)MII t1) t,peRTJaWe OfS .-.:I OS sqv6c:¥llIy shorter b patients Wlth FlT3-lTO and no 8~ rJno-l)1:Ie FlTJaIele ~ MiD! ~ W!IhOut FlTJ.lTD (m4A) ""00 w.-P1D .."". OFS sagnficantty shorter for patienls wit! FLT3-TKD «llIIPB!t:Id Mlh petlenls WIth wild-type FlTJ*es (23961 CRD (but not OS) SignlfIcal1Uy srorter for patletlts WIlt1 AILL-PTD compnd with peli8nlsWIVlout ULL-PTD (313 603 """" Noli&renoe in OFS cnl os . ) between patlenIswiIhand ntW AoIl-PTD recerorlg IIS8nSr¥e treamenllIW*1g a**lgous SCT {2395l e_ ::lflAli mutabCWlS kaizalion 01 NPM """" N ,,,,,,, CRD and OS ~ longer £or patients WIll1 CEBPA mulabalsa:mpared wrlh patients with~ CEBFl4. genes {216, 731} NoSigMIcant diIIereoce in OSbetweeIl patienls lWilh and withOut CEBFl4. mulalions f233B} EFSsignlflcanUy shorter forpatJeflts with CEBPA rnutaliolls compared Willi patients IIIIh wid-type CEBPA genes f2338} CRrate of pabellts WIth cytopIaSlTic Iocaizaboll of NPM not 191ificallUy I)/Ieren! from CRrateof pabenls WJll nudearIocaJiZatiOn of NPM in l,IIivariable analysis. Cyloplasri; IocaIzabon 01 NPM wasan intIepen(lenllaYOUr3ble prognosbc Iador for CR achievement in mulbvBl1a!e Iogislic-regres&Oll model inckIding WBC. age, NPM localizatIOn and FLTJ mutations {666} ftIl mutations N CRrate Sigoificantly betterlor patents wrtI1 NPM1 mulatiOns lhalllor palienls W1lh wi:l-type NPMl geoes {1970} ~ Sigllilicalll dillerel1C8 illCRrates between patiarllswith arid witt10ut NPMI mutations {139A. 233B} DFSaodRFS sigl1lficall~y lorIQeffor peeems willi NPM1 mlllabor1$ compared wtlhpatients W1lh wild.fype NPMl genes {602, 219l1} ~ sigMicaol diflerel1C8 fnRFS between pabenls withandWithout NPM1 mutatiorls {139A. 2338. 1970} EFSsigniflCilnlty ooget 101 patients with NPM1 mlltatforls compared withpatients with wild-twa NPMl genes {1970} ~ Significam dillerellC8 in EFSbetween patents withandwitr.out NPMl mutatiOflS {139A, 233B} Nosignificant dillerence in OSteween patients withandwithout NPM l rlllItations {139A, 233B. 602, 1970, 2198} Normal CRrales, EfS, RFS, DfS andOSsignificantly better lot patients with NPMf mutations wholackFLT3-ITD compared withpatients wittl NPMl mu tations andFLTJ-iTD or thosewith wild·type NPMI gelleS withor without FLTJ-ITD NPMl mutations do notseem to signifi- cantly alleet poorprognosis of patients with FLTJ-ITO {B02, 1970, 2198) Nosignificant dillereoces in EFSand 05 between patents with NPMl mutations andnoFLTJ-ITD compared with patients with NPMf mutations andFLTJ-ITD arid those with wild-type NPMl genes with or without FLTJ-ITD {139A/ IfTlmulations Normal Failureto achieve a CRwith standard induction chemotherapy lor patients With WTl mutations andFLTJ-ITD {2120Ai, OFS andOSsignificantly shorter forpati$nts with WTl mutallons compared With pabents Wlttl wiId·type WTI alleles {1696A} BAAle ibmaI CRrateandrate01 primary resistant disease significantly WOfSelor patients withhigh e~pression oflhe BAALC gene in blood compared willi patients withlow eJqlreSSiOn of the BAALC gene{1358} ""e..., No significant diflereooe in CRratesbeWeelI patieols withhigh aodpaLenls With lowe.pressiOn 01 the BAALCgeoe {l 35A, 216} DFS, EFS RR and OSsignificat1Uy WOfSeaooCIR significantly htgher for patients With high elpression of lhe BAALCgeoe 11 blood . compared Mth pabents withIoYt eqJreSSlon oIth8 BAALCgeoe {1J5A.. 1356, 216 } Normal CRrates, EFS, CIA, andOS SIgnificantly worse lor PlltJents widllligtl e~ioo oIlhe ERG gene in blood compared withpalieols wrlt1 lowe~oflt18 ERG gene{1J9OA, 139OB} Normal OS and RFS significantly shorter and RR higher for pallenl$ WIth high e~ of the MN f genecompared WIth pabents withIoYt elp(8SSion altha ",NI gene (9J7A) lblIiIcI by[) Mnz8k from MrOzek and Bloomtiekl {1531A).-.d MrOzek et Ill {1532} WIth pemlI$SiDn. , EFS ...... SUllYII: RFS, ralapse-frM Sl.fVival: OS, ova-aI surYiIaI; CIA, eurnulative inl:icIence of relapse, RI. relapse inQdence: OFS, d1seas&4ree SUIYMl; RR.fisk of . . .. FL1J.ITO .,.,. tandem duplalllOll of the FLngene, FLT.HKD,1IkJtlOOns 11 the tyrOSII18 kinase domiIIo offhll FLDgene, CRO. compIeIe remission dIntioo ; AIU.- n ,pnal llwldemduplicabon of118 AIU gene: SCT. stem cellrWlsplanta1ior CR. ~ IeITissIon; ". NMnal kar)otype, Acute myeloid leukaemia with reclKrent genetIC abnQIrnaliltes 11 9
  • 115. • disease. entities rather than prognostic not yet clear. There fore. the presence of These mutations are not de tectable by teeters . A small number of AML will show any of the recu rrent nanstoc ations or in- cytogene tic an alysis and are usually both NPMl and CEBPA mu tations. which versions should be identified in any AML detected by PeR. Detec tion of cytoplasrri: would no t fit well into the proposed clas- d iagnosis . In ad d ition , because of the ad- NPM by immunohistochemistry coretaes sification structure. In addition, the prog- verse prognos tic impact of FLT3mutations well wi th the molecular m ethod [6641. btl nostic signi ficance 01 the chromosome in AML with NPMI mutations. mutation similar immunohistochemical surrogate aberrations reported to occur in 5-15% of analysis 01 FLT3 should always be per- tests are not currently available lor aI AML with NPM 1 or CEBPA mutations is formed with NPM1 and CEBPA known mutations. Acute myeloid leukaemia with mutated NPM, Definition Acute myeloid leukaemia with rnnaied NPM 7 carries mutations that usually fo valve exon 12 of the NPMf gene AbetraW cytoplasmic expression of nucleophosrTrl (NPM) is a surrogate marker of this gefIe mutation 16661. This AML type IreqJef1l, has myeIomonocytic or rrooocstc feall.Jes and typically presents de novo in ~ adults with a normal karyotype. The WHO Working Group ass igned !his lesion 10 a group of provisional ennnee ICD·Geode 9861/3 Synonym Acute myeloid leukaemia wilh cytooasrc nucreopnosrsn (NPMc+ AML) . Fig. 6.101 Acute myeloid leukaemia with NPAlt mutations and myelomonocytic features. A Bone marrow biopsy showing complete teplacemell1 by large blaSCs With abuooanl cytoplasm and IoIded nuclei. B l elillaemic cells are CD34-negalive. C l eukaeJTllC eels show aberrant cyloplasrric expression of rkJdeopilosrrWfl (NPM). D EXpt"ession of Epidemiology C231nodeolin is restricted to Itle nucleus. NPM1 mutation is one of the most COOlTOl recur ring genetic lesions in AML [283, CEB~ +5 _ ~ 602.666.667.2198.2331 1. Prevalence CEBPA+loC.L-PTD+ 1.2% increases wit h age, occurring in 2-8%ci c hil dhood AM L an d 27% -35% of adLJII FLJ3.TKD+/KL· PTD+ 0 .8% AML. NPMI mutat ions occur in 45- 64%ci FlJ3.TKD+ 2."% adult AML w ith a nor mal kar yotype 1283 R.T3-lTD+/CEBPA+1.6% 351, 439, 666.2 198, 2331). This disease Fl T3-lTO+IMLl·P"TO+ 2."% appears 1 show a fem ale pr ed ominance 0 FlT3-lTO+ 8 .1% Clinical featu res Acute myeloid leukaemia with NPMl NPM+lFLJ3.TKD+/ } O " CEBPA +/KL-PTD+ " mutation usually pre sents without a his- tory of a MDS or MPN {6661. Patients otten NPM+tf:;Un;::;: }o,% ., exhibit anaemia and thrombocytopenia. b ut onen have high er whi te blood cell and NPMl+IFLT.J-TKD+/ } , _ platelet coun ts tha n other AML types CEBAI+ -" ,. 16021. Patients may show extramedullary NPAI, +,F n.rTO+l } , " l involvement. the most frequently affected CEllA" sites be ing gingiva, lymph nodes and Skm. NPtrI1+,f=LT.J-m)+ } , " / FLJ3.TKD+ - Morphology and cytochemistry NPM1+.<:ESPJIl,+ 3. ~ There is a strong association betweee Fig. 6.15 Pie dlaf based on 2"6 pabent$ analyZed tor Itle Ilf99l!IlC8 01 mutations in Itle NPUI and CEBPA genes. acute myelomonocytic and acute rrceo- FLT3-ITD. FLT3-TKD and AIU.-PTD. E.actI seclof nIc3les the peIC8flIllge 01 pabenIs harbotmg one Of ITOOl 0I1he cytic leukaemia and NPMI mutation {666 abemenliOlllld muIabons WT rocates pabeftS WlIh only ~ alleles01 genes tes1ed. FromIkozek (If 11I.(1532) . 6671: notably. 80-90% of acute rTIOf()o lnlltdapled!ram 00IVlllf (If Ill. (602}. cvtc leokaerntas show NPMl mctetce, 120 Acute myelOid leukaemia and related precursor neoplasms
  • 116. However, N.PM1 mutations are also de- tected in AML with and without ma turation and in acute erythroid leukaemia. A subset 01 cases shows multilineage dysplasia. These cases usually have a norm al ~aryotype and the blast cells are CD34 negative. The 8 M biopsy is usually markedly nvcerceuutar. Bone ma rrow blast percentages are generally higher in AML with muta ted NPM1 than in other acute myeloid reukaermes with a normal karjOlype 1 . 6021 The diagnosis relies on the identific ation ~ the genet ic lesion by molecular tech- !1IQUE!S and/or imm unohistoc he mic al detection in paraffin sectoos of aberrant cytoplasmic expression of NPM 16671. mronostaining with anti·NPM antibodies reveals involvement of two or ITK)(e 8M lineages (myeloid . monocytic . erythroid. megakaryoc ytic ) in the vast majority of « ML Wlltl NPMl mutation 116981. The van - Fig. 6.16 W*eage IMIlvement in AAlt. WItll NPM1 mutabons. A Bone m<mlW biopsy Massive replac:eITetlt by . ab~ lty of 8M cell types showing NPM 1 myeloid blasts wittl maturalJon; !here are also megakaryocyles and occasional irTIrn<I~ erylhnlid eels (iIflOIW). rrutations accounts for the wide rrorpro- 8 The same case as (A). Myeloid blasts (double arrtIlltS). rnegakarrocyles and mnaIue er)1tWOiCI eels (iIflOIW) sIlOW logical spec trum of this leukaemia. abe mml cytr;lpIasri: po$l ~vity lor NPt.I (blue ). Immature erythroid eels (arrow) Ill! doubIe--slained lor gIytophonn (brown) andNPM(bkJe~ C Bone marrow biopsy. UinmaIydilIenlnbaled llaIte myeIold leukaemia wrlh NPM1 rllIlaborls, occasional immature g~ erythroid cells are present 0 The same caseas (C). Myeloid bIasls and Immunopheno type imrnatIR erythroid eels (amlW) showcytoplasmic eKl)feSSion of NPM. In addition to myel oid an tigen s (CD13, CD33. MPO), the blasts in AML with NPM I mutalion frequently express markers 01 monocytic differen tiation , incl uding C0 1 CD 11b and the macrophage- 4, restricted CD68. The roost striking inYnuno- -c phenotypic featu re 01 AML wi th NPM 1 , 2 3 ..! 11 7 89 .)]"12 mutation, which is independent of the NPM1 gMfe ~ • • • • • • .. -iF .. -..::::::J- degree of maturation of leukaemic cetls, I is the lack of expression of CD3 4 (666). NPOI u•...,r••" By immunohistoch emistry on p araffin .. . . _ . . .cc •••••• ~ . . u •• •• ~. r . . • . • c • • c• • • •• • • • • • • •• • • N• • • " •• " •• •n c . t • •• ••• t co . sections, antibod ies aga inst NPM show N ••• " ••• • , eu c . f e characteristic abe rrant exp ression of N e .aoc••••• U . eOT c •• tc. _• • . the protein in the c yto plas m of leuk aem ic NU H D ............. . ....... c .C<. e ~ . • •." ." 04" . . 04 . cells(6661 In co ntrast, positivity for C23/ . N. . ., f co • • CTeTT""ee • •• . u.u •• , • • ............., =_ . .- - • • • •04 04 nucleolin (another major nucleolar protein) isrestricted to the nucleus of leukaemic cells. Immunohistoc hemical detection of caoorasrnic NPM is predictive of NPM I WI~ryp. NPM .-- • _ ---- ---...., E _ 8ognol (NEll) ....... .-- protein _ . . - - . s . - lNt-i euatoos 16641. since the mutations c ause critical changes in the structu re of NPM =- . T_ . _ - native protein (c haracteristically located " the nucleolus), leading to its inc rease d ..., , COOH,, export tram the nucleus and aberrant accumulation in the cytoplasm. M ur.redNPM leul<aemle protein , , II I • Genelies Acute myeloid leukaemia with NPMl, ITkrtation is usually associated with a nor- Fig. 6.17 AclJte myebd leukaerria with NPM1 "-IlaIions. Mutations usualy 0lXIS at exon 12 of tlle NPAlI gene. The irs! i:lenlified NPU1rIlIlabons (A" F)Ill! shown (666}. MiDtIon A1$fie most hqI.Jenl acaulbng lcr 70-8010 01 cases. mal karyotype . however. 5- 15% of AML AI rn.Jtabllns feSUIt in a:mnon changes at fie e.tllmwu (COOH) 01 fie WlJd.type NPM protein. These dlanges (asl!lnst W!ttl NPMt mutation show chromosomal in the NPM nwtated proIeIn) c:onsisl of replacement of ~s) aI posibon 288 and 290 and aeation d I ~ aberrations 1666, 667J, inc lud ing +8 and export sqJaI (NES) motil. whiCtllre boIh responsible lor the inc:reased nuclear eJPl and abemIrlt t)lcIpliIsrrC de/(9q) 121961 NPMt m..rtabons are usually . aca.oTUabon of !he NPM 1TlJIlwits. Acute myelOId leukaemia With recurrent genetic abnormalities 121
  • 117. favou rab le prog nosis to AML with a chro- - A POCO 000 1 - B P<o.OO(U mosomal aberration or with multilineage d ysp lasia. l- 1- .._.. NPMt-IFl r:J.fID-I l_ - CESPA- Acute myeloid leukaemia with mutated CEBPA • ~- I: CE8IA - NPM r-tFl rJ.,lTO"" Definition ~_. Acute myeloid leuk aemi a with rnctaiec .-. • .-. CEBPA usually meets criteria for AML maturat ion or AML without maturation, bul • • • • • T_•_ • • • • • - • , • • • •T_ • , • _ ••• some cases may sho w myel ornonocyliC or monobtastic features. This leekaema usually presents de novo. l- - C NPM""/FL T34TD-o P-O.71 - !: - 0 _ ", P-O.OO3 The WHO Working Group ass igned ~ lesion 10 a group of provisional entities ICD-Ocode 9861 /3 • .- Donor i- - Epidemiology CEBPA rrc tanons occur in 6-15% 01 de t No-Donor j- - Donor , . novo AML and in 15-18% of AML W1:tl norma l karyotypes 1216, 737, 12801 rtee . •• are no apparent age or sex d ifferences between CEBPA mutated and l"IOI"HTUIale:! No-Oonor • • AML [20401 • , • • r_ _ • • • • • • • • • • • • • • , • • • T_ _ Clinical features Acute myelo id leukaemia with meteredFig. 6.18 Prcq10sis ofAML paltents A,B ThegenotypesNPM -JFL1J-lTlY" and CEBA<I" arelaYCUable progllOSOC .markers. C.DUnivariate donor IWSUSno-donof analysis onreepse-rree survival 01 AML with normal karyolype in fi~ CEBPA tends to have higher haemogkbncompleIe remission. acttIIding III g&IlOtype. The donor group ....as defifled by !he availability01 a HLA-maIched larrily levels . lower p latelet counts. lower lactaedonor comprising a maId! in toe loci HlA-A, HLA·B and HLA-DR C Results in AML with li!VOUfab~ genotype dehydrogenase leve ls and higher PBNPMf"lFlTJ-lTO""; (0) !he results in AMl wilt! adverse gerotypes FLT3-/1D"" and NPI,/1"ICEBPA"JFLTJ.lTO""; bl ast cell co unts when c ompared toOnIyAML withactYerse gellOtypes (0) benefit from allogeneic stem celIlransptanlalion. From Sd1lenk RF 1:/1aI. {1962A J CEBPA non-mutated AML. This leukaemia type also has a lower frequency of 1ym- phadenopathy and myeloid sarcoma 1216, mutuallyexclusive of the recurrent genetic Prognosis and predictive factors 7371.abnormalities tha t define the AML entities Acute mye loid leukaemia with mutateddesc ribed in the p rec eding sec tion 16651 NPM1 typ ically shows a good response to Morphology and cyt ochemistryand with par tial tandem duplicat ions of induction the rapy 1 666 ) Acute myelo id There are no distinctive morpholog ic lea- MLL and CEBPA muta tions, although con- leukaemia with mutated NPMI and a normal tures ot AML with normal karyotype an~currence of these abnormalities with karyotype, in the abse nce of a FLT3-ITD CEBPA mutations. but the vast majority dmutated NPMI have been reported 1602, mutation. has a characteristica lly favourable cases have features of either AML withoJ2198 1. Ab out 40% of AML with NPM1 p rognosis {283 , 60 2, 1970 , 2198 , 2331 1 . Of with maturation Less commonl y. casesmut ations a lso ca rry FLT3-ITD (6661. The coexistenc e of FLT3·ITD mutations is have monocytic o r mveromonocvtc lea-NPMl mutations ap pear to precede FLT3- associated with a poorer prog nosis. b ut tures. Three percent or more of the blastsITO and these Ieukaermas are mo re Ihese patients still appear to have an im- are myelope roxid ase or Sud an black Bgenet ically stetne during disease evolution proved prognosis c ompa red to AML that positive, and most cases are non-specific1439, 21981 AML wilhcytoplasmic mutated . is NPM1 negative and FLT3-ITD positive este rase neg ative.NPM1 shows a di sti nct ge ne expression 17461. Younger ind ivid uals with AML and ap rofile characterized by up- reg ula tion of norma l karyotype exhi biting the genotype Immu nophenotypeHOX genes 119. 233 11 that di ffers from NPM 1 mutated!FLT3-lTD negat ive show a Leukaemic blasts usually express one (Jth at of other AML typ es. inc lud ing AML prog nosis that is comparable to that of more of the myeloid-associated antigens.with MLL rearrangement 11539). AML with t(8 ;21)(q22;q22) or inv(16) CD13. CD33, CD65, C01 1b , and COIS (p 13.1q22) and may possibly be exemp ted There is usually ex pression of HLA·[)APostula ted normal counterpart from allog ene ic stem cell transplantation and CD34 on the majority of blastsHaenatopoenc stern cell 113941· in first complete remission 16021. It is not Monoc ytic markers such as C014 anc known whether a NPM1 mutated;flT3-lTD C064 are usu ally absent. C07 is preset nega tive genotype also confers a in 50-73% of cases, while expression It122 Acute myelotd leukaemIa and related precursor neoplasms
  • 118. CD56 or otner lymphoid antigens is Postu lated normal co unterpa rt or t(8:2 1)(q22;q22). The significance ofuncommon 1216. 13081. Haematopoietic stem cell. FLT3-lTO on the prognosis of this group (s currently unclear. with small studies sug-Genetics Prognosis gesting either no impact or a negative im-Seventy percent of A ML with CEBPA Acu te myeloid leukaem ia with a normal pact on prognosis 1737, 17801. Althoughmutation have a normal karyotype . karyotype and CEBPA mutation is associ- uncommon , the prognostic significance ofFl.T3-lTD mutations occur in 22-33% of ated with a favourab le prognosis. similar A ML with CEBPA mutations and othercases. to that of A ML with inv(16)(p13.1q22) chromosomal aberrations remains unclear. Acute myeloid leukaemia With recurrent genetic abncemanoes 123
  • 119. Acute myeloid leukaemia with DA ArOOr R D . Brunning A.P<xw< JW VardllTal myelodysplasia-related changes A .Orazi BJ. Barn MoM. LeBeau P.L Greertlefg Definition Epi d emiology morphology, dysplasia must be present in Acute myeloid leukaemia (AML) with This ca tegory of AML with mveiccysptasia- at least 50% 01 the ce lls in at least two 8M myelo dysplasia-rela ted changes is an related cha nges occurs mainly in elderly ce ll lines. Dysq raoulo poresis is character- acute leukaemia with 20% or more peri- pat ients an d is rare in chi ld ren 1913, ized by neutrophils with hypograOlJa phe ral blood (PB) or bone marrow (8M) 12691 Although the d efinition 01 rnultitin- . cytoplasm, hyposegmented nuclei (pseLti> blasts with morphological features of eage dysplasia is variable in the literature , Petqer-Huet anomaly) or bizarrely seg- myelodysplasia or a prior history 01 a this category appears to represent mented nuclei . In some cases, these myelodysplastic synd rome (MDS) or 24-35% 01 all cases of AML 1 69, 869 , features may be more readily identiliedoo myelodysplastic/myeloproliferative neo- 1493 , 2465). PB tha n BM smears. ()yseryItlropoiesls IS plasm (MDSlMPN), or MOS-related cvto- characterized by megaloblastosis, karp- genetic abnormalities, and absence of Clinical leatures rhexis and nuclear irregularity, lragTllll1a- the specific genetic abnormalities of AMl Patients with AML with myeiooysprasia- han or multinucleation. Ring sideroblasts, with recurrent genetic abnormalities. Pa- related changes often present with severe cytoplasmic vacuoles and periodic acid- tients should not have a history of prior pancytopenia. Some cases with 20-29% Schiff (PAS) positivity are addlt~ cytotoxic or radiation ther apy tor an unre- blasts, especially those arising from MDS features of cvsevtnroooesrs. Dysmega- lated d isease . Therefore , there are three or in ch ildhood , may be slowly progressive. karyo poiesis is characterized by micro- possible reasons for assig ning cases to These cases, w ith relative ly sta b le PB me gaka ryocytes and normal sized r:J this subtype: AML arising from previous co unts for weeks or months, co nsidered larg e megakaryocytes with non-lobulated MDS or MO S/M PN ; A ML w ith an MOS- refrac to ry anaemia with exc ess b lasts in or multiple nuclei. Dy sp lastic megakaryo. related cytogenetic abnormality; and AMl transformation in the Frenc h-A mer ican- cvtes may be more readily appreciated n with multilineage dysplasia. A given case British Cooperative Group ctassmcauon. sections than smears 169, 7421. may be assig ned to this subtype for one, may behave clinically in a manner more sore cases wiU not have sufficient rcoees two or alt three reasons (Table 6.02). similar 10 MDS than 10 A Ml. cell 8 M elements 10 adequately assessb multilineage dysplasia or have sufficietw; ICD-O code 989513 _ and cyt """,,",stry non-blast cells but do not meel the crilera Most, but not all cases in this category of described above for a morphologic Synonym AML have morphological evidence 01 nosis of AML with multilineage dysplasia Acute myeloid leukaemia with multilineage muniuneaoe dysplasia which must be These cases are diagnosed as AML dysplasia. assessed on well -stained smears 01 PB mveiodvsptasta-retated changes by ee and BM. To classify an AM L as having detection of MD&-related cytogenetic aD- mve covsoasta-retateo changes based on normalities anellor by a prior history ofMDS. • - Fig. 6.19 Acute myeloid le~~ with myelodysptasia-felated changes (murtilillllage dysplasia). The marrow aspirate shows numefOlJS I9"8nulaf blasts as wei as actIuII: hypogrardar neutrophiIs with dul1lled nucleardWomatin and eryttftid preanors MttI irreQlAar nuclear am..n. AA small. llypoIobated rnegakaryotyIe is IQS80I al lhe txb. BAIigher magOOicaIion 01 anoltl8fcase showing rlICIre irregIJar nuclearfeatures 01 eryIhroi:I l)"eanors and ~ wiIhcbnped IIUd&ar etwomatn 124 Acute myelOtd leukaemia and related precursor neoplasms.
  • 120. Immunophenotype t(2;1 1)(p 21;q23 ), if not associated with Table 6.02 Criteria lor the diagnosis of AML withImmunophenotyping results are variable prior cytoto xic therapy, should be classified myelodysplasia-relatedfealu!&S.dueto the heterogenei ty of the underlying in this group rath er than as a variant ~ 20% blood Of mam;lW blastsgenetic changes, In cases with aberralions translocation of 11q23 , AND01 chromosomes5 and 7. a high incidence Cases of AML with multilineag e dysplasia Anyof !tie Ioi:lwingoICD34, terminal deoxynucleotidyl trans- may carry NPMI and/or FLT3 muta tions PreW:lus hislDry of myeIodysplaslic syndrome!erase (Td T), and CD7 expression has [23561. Most NPMI mutated cases would MyeIodysj::QsbC syndrome--relaled L)IogenetIcbeen reported 123241. In cases with an- be expected 10 have a normal karyotype, abnormalrty (seeT able6.03)ieceoent MOS. CD34+ cells frequently CD34-negative blasts and no history of Mullilineaga dysplasiaconst itute only a suboopuraton of blasts prior MDS 120151. However, the presence ANDm may have a stem-cell related immuno- of an MDS-associated karyotypic abror- ......."bdhpheootype with low expression of CD38 mality should take diagnostic precedence ?nor cytlItWc therapy lor an I.MlIaIed diseaseM"dkx HLA-DA. Blasts often exp ress pan - over the detection of an NPMI or CEBPA RlICllfTing ~ abIllllT1lahl) as descnbed in AMl-Mlh reamlOI genetic abroomIakbes.myeloid markers (CD13. CD33). The re is mutation for classification purposes untilTequently aberrant expression 01 CD56 the significance of such rare genet ic c0m-and CD7 116231. The maturing myeloid binations is clarified . In patients wIth AML Table 6.03 CytlgenetJc abnorr!alIbes suIIicienI mcells may show patterns of antigen ex- with multilineage dysplasia and a nQ{ma l <iII(p105e AM.. will myelodyspIasia-leatLRs wnencesson differing from thOSe seen in nQ{- karyotype. information regarding the mu· ~ PB or8M blasts are presett.mal myeloid development, and there may tational status of NPMI, CEBPA and FLT3 (.oorpe. ~ ee alterations in the light scatter proper- may provide important prognostic infor-DeS of maturing cells, particularly neutro- mauon. and the presence of these muta- UnbtIIItdd aMoonaiiliestfWs, There is an increased incidence of tions should be noted along with the ·llde(7qlTUlKinJg resistanceglycoprOlein (MOO-1) diagnosis of AML with myelodysplasia- .-5qJexpressiOn in the blast cells 11206, 1268, related changes (multilineage dysplasia) ~ l1q)l l1p)12691. 123561. ·131de1(13q) del(t1q)Genetics Differential d iag nosis del(12pj/l(l2p)Chromosome abnormalities are similar to The principal differential d iagnoses are "l9q1bose found in MDS and often involve refractory anaemia with excess blasts , idic(X)(q13)gain or loss of major segments 01certain acute erythroid leukaemia, acute mega- &tI1l11Ud abnoonaiitieschromosomes with complex karyotypes karyo blaslic leukae mia and the other cat- t1:11 ;t 6)( q23;p13,3)"and -7/del(7q) and -5/del(5q) being most egories of AML. not otherwise specified t1:311 )(q26.2;q22.1)"ccmmon 11 269 , 1530 , 1641J, Additional (NOS). Caref ul b last cell counts. adner- t1:1:3)(p36.3:q2t ,1)abnormalities that are considered suffi- ence to the diag nostic criteria for morpho- t{2:11)(p21:q23)"ocient for inclusion in this ca tegory are logical dys pl asia and evaluation for 1(5;t2)(q33:p12)given in Table 6.03, While trisomy 8 and MDS· re lated c ytogenetic abnormal ities t(5;1)(q33:qtl .2)del(20Q) are also common in MOS, these shou ld resolve most cases, with this ca te- t(5;11)(q33;p13)ffJdingsare not co nside red to be d isease- go ry having priority over the purety morpho- t(5;10){q33;q21)specific and are not, by themselves, suf- log ic ca teg ories of AML , NOS, For t(3;5){q25:q34)ficient to co nside r a case as AM L with exam ple, a ca se with >20% 8 M myeio -myelodysplasia-related c hanges, Similarly, blasts, multilinea ge dy spla sia, ove r 50% >3 unrelated abnomlalities none of which are ,bss of the Y ch romosome is a non- BM erythroid precursors and monosomy 7 includedin theAML withrecurrent genetic abnor -specific find ing in o lder men and should should be c onsidered as AML with malities subgroup: such casesshould be dassjfiedoo! be consi dered sufficient for c yto- myelod ysplasi a-reiated c hanges rathe r in the aPPfClPriate cytoger.etic group.[Ie!1etic evidence of this d isease ca tegory than acu te e rythroid leukaemia, Simila rly, 0 These abllormalities most commonly occur inBalarced translocations are less common a case with over 20% 8 M megakaryo- tnerapy-ffllated diseaseand lherapy-relatedAMLin tnis disorde r, but when they occur are blasts and multilineage d ysplasia would should be excluded before u~ng these abnormali-of:en franslocations involving 5q32-33, be considered AML with myelod ysp lasia- lin asevidence lor a diagnosjs of AML withT t(3;5)(q25 ;q 34 ) is associated with ile related changes (megakaryoblastic type), myeiodysplaSlB-related features.rrOtilineage dysplasia and a younger ageal presentation than most other cases in Postulated normal counterparttis disease group 1661 In addition, AML . Multipotent haematcooreuc stem cell. between cases with and without priorW1h inv(3)(q2 1q26.2), t(3;3)(q21 ;q26 .2) or MDS 1691. recognition of cases with priorW#l t(6;9)(p23:q34) may show evidence of Prog nosis and pred ictive fact ors MDS and relatively low blast counts mayrru/tilineage dysplasia, but these are now Acute mye loid leukaemia with myelodys- identify cases with less clinically aggres -:ecognized as distinct entities in the AML plastic features generally has a poor sive disease. Some cases with prior MDSMIll recurrent genetic abnormalities prognosis with a lowe r rate of ach ieving and 20-29% 8M blasts, consideredgoup and should be classified as such . complete remission than other AML types refractory anaemia with excess blasts in*wever, cases with the specific 11q23 169. 742 , 1269 , 1493 , 24651. While the re transformation in the French-American-wrangements. t(11 ;16)(q23;p13,3) and are no overall prognostic differences British Cooperative Group ctessucatcn. Acute myeloid leukaemia WIth myelodysplaSIa-related changes 125
  • 121. may behave in a manner rrore similar toMOO than ome AML. These cases . as well •• as cases wi th myelodysplasia and justunder 20% blasts, require regular moni- toring of PB counts and 8M morpholOgylor changes suggesting disease progres- sion to overt AML. Although AMl with mu ltilineage dysplasia Iis generally associated with a poor prog· , ! nests. several studies have not foundmorphology to be a significant parameterwhen using multi-variant analysis thaI alsoincorporates the results of cytogeneticanalysis, high risk cytogenetic abnormal- --t_ 4...ities being more significantly associated • ,with prognosis {869, 2356, 24651. There-fore, mUltilineage dy splasia should b e v.... ,,"" .......conside red as a po ssible indicator of high Fig. 6.20 Survival curve lor cases of acu te my oidleukae mia with adverse cytogenetic find ings in the "tRC-AM IO el lrisk cy togenetic abnormalities, bu t in the trial Repr oduced from Gri wade Det al. {MB}. mabse nce of such abnorma lities. may notbe important. In such c ases, fluorescencein situ hybrid ization (FISH) stu dies for above, at this time cases of AMl with MOS without assoc iated dysplasia idl!f$-MO$-related abnormalities may be useful. MOS-related cytogenetic findings and ueo at the lime 01 AMl diagnosis woUdIt is cu rren tly unclear whe ther a NPM1 one of these mutations should be diaq- be considered ~ AMl with myelodysplasaa-posl livefFLT3-negative genotype in AMl nosed as AMl wi th myelodysplasia- related changes (following prevoswith multilineage dysplasia confers the related changes as well as noting the MOSt; and a case with prior MOS. dys-same good prognosis as in other AMl mutation detected. plastic features and monosomy 7 WCllilwith NPM, mutations. Cases of AML with be considered "AMl with rnyeIoctyspIasemultilineage dysplasia and NPM1 meta- Diagnostic term inology related Changes (fotleJoNing previous Ml.linone usually do not have adverse cyto- Because there are different pathways to a MDS-associated cytogenetic a~genetic findings or a history of prior MOS diagnosis of AML with myelodysplasia- and muttilineage dysplasia). Cases120151. However. the clinical impact of related changes, which upon further NPM1, CEPBA and/or FLT3 mutatll)lSmutation status versus the presence of study may have clinical differences, it is should also indicate the mutation hndrYJmultumeaqe dysplasia requi res more recommended that the reason(s) for (r.e. "AMl with mverocvsotasta-reraiecinvestiga tion. Therefore, it is not yet clear dia gnosing a case as such be included in changes (multilineage dysplasia) aMhow cases of AML with multilineag e dys- the di agnosis. For example , a c ase di ag- NPM1 mutation"). Finally, because ollhep lasia without prior MOS or MOS·related nosed solel y on mo rphology would be possible cli nical heterogeneity of casescytogenetic abno rmalities and with an considered "AMl with myelodyspla sia- with low blast cell cou nts (20-29%), tt:ENPM1 mu tation or a CEBPA m utation related changes (rnultitineage dysplasia)": b last count should be cl early stated in t~should be c lassified . How ever, as noted a case arising from p reviou sly diag nosed repo rt.126 Acu te myeloid leukaemia and related p recursor neoplasms
  • 122. I"" Therapy -related myeloid neoplasms JW. Vardiman DA Arber E. Malutes I. Baumann RD. Bruming J Thiele RA Larson Definition the rap ies such as hydroxycarbamid e Inis category include s therapy -rela ted (hyd roxyu rea), rad ioisotop es, L-aeo araq- acute mye loid le ukaemia (I·AML). rnyelo- inase and naematcootetrc growth teeters dysplastic synd rome (I -M DS ) and m yelo- have been sugg ested to be reukae mo- dysplastic/myelop ro life rative neoplasm s genic, their pr imary role in thera py-related (t-MDS/MPN) occurring as late compliea- haema tologic neoplasms. if any. is not ons 01 cytotoxic chemotherapy an d/or clear. Characteristic clinical, morphologic -adtatlOn therapy adminis tered lor a pr ior and genetic features often relate to the «lPIastic or non-neoplastic disorder. AI- previous ther apy received . h:luJh some patients may be d iagnosed nnptdogicatty as 1 -"-105, t-MDS/MPN ()( Sites of involvement ~AML according to the number 01b lasts Peripheral b lood (PB) and bone ma rrow Fig. 6.21 Therapy.retaled AML with t(9;11)(p22;q23). present. all of these therap y-related neo- (BM) are the princip le sites of involvement . This pabenl deYeloped 1 -AMl. 1essltlanone yearfoIow. plasms are bes t considered together as a ing instilulion oIlherapy lor osteosartoma. The therapy IIlJque clinical syn d rome . Exc luded fro m Clinical features included both alkylabllQ agentS and ~ II in- mig categor y is tran sfor mati on of MPN Near ly an equal number of patient s give a hibilorn. srce it is etten no t possible to determine history of treatment fo r a p revious baema- if !his is disease evolution or therap y- tologi cal ma lignancy as for a non -haema- related. tolog ical solid tumo ur. How ever. 5 - 20 % of in practice many p atients have rec eived patients are reported to have rece ived cy- polychemotherapy that includes both 992013 totoxic therapy lor a rco-oecoasrc disease. classes of drug s an d the boundary be- A smlar num ber develop a therapy-related tween the two categories is not always &,nlnym myeloid neoplasm afte r high dose sharp 120411. Therapy-related acute myeloid chemotherapy and autologous haemato- ielJ:.aemia. NOS. porenc stem cell transplant for a prev i. t.1o<pIloIogy ously treated malignancy 11 433. 20411 . The majority of patients present WIth -k>Iogy Two subsets of t-AMlIt-MDS and t-A MU t-AMlIt-MDS associated with multllineage Therapy-related t-AMl.../t-MDS and t-AMLJ t-MDS/MPN are generally recognized , dysplasia . Commonly, but not invariably l.M DS!M PN ac count fo r 10 - 20% of a ll The most common occurs 5- 10 years in such c ases, a history of p rior therapy cases of AML, MDS and MDS/M PN 11278, afte r exposure to alkylating agents an d/or with alkylat ing agents and /or rad iation 1433, 1536 1 The incidence among pa- . ioniz ing rad iation. Patien ts often pr esent therapy is elic ited and cytog enetic stud- ieras treated w ith c ytotoxic agents varie s with t-MDS and ev idence of 8 M failure ies rev eal abno rmal ities of c hromosomes ElC cording to the underlying di sease and with one or mul tiple cyto penias, although 5 and/or 7, o r a comp lex karyotype , Nev- fe treatment strategy. Any ag e group a minority will present with t·MDS/MPN or ert heless, dysplasia may be seen in some rray be affected b ut the risk associated with overt t-AML This c ate go ry is com - c ases wit h balanced tran siocauons as lIllh alkylating agent or rad iation therapy mon ly associated with unbalanced loss of well. The P8 shows one or more cvto- jjerlefally increases with age whereas the genetic material . often in volv ing chromo- pemas . Anaemia is almost always present rsillor those treated with topoisornerase II somes 5 and/or 7 . The second category and red cell morphology is cha racterized IIhbIlors is similar ac ross all ages 1651, of t-A ML/t-MDS and t-A ML/t-MDSIMPN in most cases by macrocytosis and poik- 12781, encompasses 20-30% of patients. has a ik::x:ytosis, Dysplastic changes in the neutn> latency period of about 1- 5 years, and p hils include abnormal nuclear lobation, E"*lJy follows neannent with agents thai inte ract particularly hypolobatoo, and cytoplasmic Therapy-related neoplasms are thou ght to With DNA tcoosorerase II (topoisornerase hypogranulation . Baso philia is freq uently bethe conseq uence of mutational eve nts II inhibitors). Most patient s in this subset present 11 4721. The 8M may be hyper. mceo by cytotoxic ther apy, Som e indi- do not have a mveioovsotasnc p hase bu t ce llul ar, no rmcceuurar or twpoc euuiar. OOualsmay have a heritable predis position pre sen t initia lly with ove rt acute leukaem ia and slight to mark ed 8M fibrosis occurs due topolymorphism s in genes that affect tha t is ofte n assoc iated with a bal anced in approximately 15% of c ases. Dysgranu- drug metabolism or DNA -repair rnecha - cororoscrat translocation 1 651, 1716, 20411 , lcpoiesis and dy serythropo iesis are pre s- ~sms. but for most cases the und erlying A lthough it may b e useful to c onsid er ent in mos t patients , Ring siderobla sts are 08thOgenesis rema ins uncertain 11899 1. t-A MlIt- MDS and t-A MU t-MDSIMPN rep orted in up to 60% of cases and in Cy1oIoxic agents commonly imp licated as being alkylating agent and/or rad iation- some c ases exceed 15% of the erythroid ire istec in the Table 6.04 . Although other related or as top:lisctnerase II irtlibitor-related. precu rsors. Meg akaryoc ytes ....ary in nurn- Therapy-related myeloid neoplasms 127
  • 123. 00 000 00 O· __ 000 0 0°0°° 00.p~ . • _ ° o 0000°000 &0 , _000 00 0 0 00 .10.Q 0 0 000 00 0 00 ~ 00 0 00 00 .. ° 00 0 1 A O OO. O O O_O ~O!?C . 0 0 , •Fig.6.22 Thefapy-relaled MDSlAML This 42-year-old man was lrealed withABVD therapy lor dassical Hodglin IymJ:tloma but retapsed 161T1OflthS laterandwas!Jven 9vagechemolt1erapy and radiolt1erapy, Two years later he presented W11t1 pancytopenia in l!le PB(A), a BM asprate (8) and BM tMopsy (C) stlowtld ilCteased bass and mullili1eailedysplaSia. A complex karyotype Jnduded lossof d1romosomes 5 and7. ber but dysp lastic fo rms of variable size associated wi th these chromosomal to their de novo counterpa rts 1681. Blastswith rnooo- or hypolobated or widely sep- abnormalities 136. 1886 . 2034 1although a are generally CD34+ and express pan-arated nuclei are seen in the ma;orlty of lew cases may pr esen t as MDS or have mye loid markers (CD 13, CD33), There 1$ca ses 11472, 164 71- The percenteae 01 dysplastic teatures as well . Many cases freq uent aberrant expression of CD56b lasts also varies but in patients present- fall in the categories of acute monoblaslic and lor the lym phoi d- associated markering with a rnyelodysplastic pha se a lmost leukaemi a or mverononocvtc leukaemia. CD7 . The ma turing myeloid cells may50% will have less than 5 % 8 M b lasts but ca ses with granuloc ytic d ifferentiation show patterns of antigen expr ession that11472, 2026J About 5% of pat ients have al so occur Case s mo rph ologi ca lly (and diff er from that see n in norm al myeloidfeatures of MDS/M PN, suc h as c hronic cytogenet ica lly) identical to those ob- development. and there may be alterationsmveromooocvnc leukaemia 120261 Al- . served in all of the subtypes of AMl in the light sc alier properties of maturingthou gh patient s presentmq With rnyeio- With rec urring cytogenetic abnormalities cells. particularly reutropnus .dyspl asia and cvtoperaas may be have been descri be d , inc luding acutedesi gnated as l-Moo or t-AMl depending pronverocvnc leuk aem ia , Such cases Geneticson their mo rphology an d b la st counts. should be designated as t-AMl with the The leukaemic cells of ove r 90% eXsuc h subclassification may lack clinical ap propriate cytogenetic abnormality indi - patients with t-AMUt-MDS show ansig nifica nce 120261. c ated. e.q. t-AML with t(9; 11)(p2 1;q23 ). abn ormal kary ot yp e , The cy tog eneticIn 20-30% of c ases, the first man ifestation Cases of lymphoblastic leukaemia (All ) abn or ma lities often co rre late with theof therapy-re late d mye loi d neoplasm is also occur in this group , usually associ ated laten t pe riod be tween the initial l herapyov ert acut e leu kaemia without a preced- with a t(4 ; t 1)(q2 1;q 23) c hromosomal and the onset 01 the leukaemic disordering myelodysplastic phase , Often , but not abnormality 11022,19841. and With the pre vious cytotoxic therapyinvariably , these cases follow toposo- 11254.1433,1716, 1886,20411. Approx-merase II inhibitor tnerapy. The majority of Immuoophenotype imately 70% of patients harbour urea-the cases are associated with balanc ed There are no specific immunophenotypic anced chromosomal aberrations. mainlyrec urren t c hromosomal transtocanons findings in t·AMUMDS ()( in t-AMljt-MDS/ whole o r oaruat loss of ch romosomes 5that frequently involve 11q 23 (MLL) or MPN. lmmunophenotypi ng stud ies reflect and /or 7, that are often assoc iated wit!l21q 22 (RUNX1) , and hav e morphology the heter og eneity of the und erly ing mor- one o r more ad d itional ch romosoma lthat resembles de novo ac ute leukaemi a ph olog y and often show c hanges similar abnormalities [e .g . d el(13q ), del(2OQl, d el( 11q ), del(3p), -17, -18 , -2 1, +8} in a complex karyotype. These changes are usually associated with a long latent pe- riod . a preceding myelodysplashc phase ....kylating agents or t-A Ml with dysplastic features, and Melphalan. cydophosphamide , nitrogen mustard, cI*lrafnbldl. MuIIM, carboplalin. eisplabn , alkylating agen t and/or rad iation therapy dacarbazirle, procarbazine.carmustine. mitomycin C .lh~epa,lomus ~ne. etc. The remaining 20 -30% of patients have Ionizingradiationtherapy balanc ed c hromosomal transloc aticns large fields IfIcIuding active bone marrow that invo lve rearrang ements of 11Q23 [including us,11)(p22:q23l and t( 11 :19 ) Topoi_ aMIl inhibiton (q23 ;p13l] . 2 1q22 [inc lud ing t(8;2t) EIOpOSide. 1eoipO!iiOe. dolOfban, d8ulorIbcin.lIWJ.dnlrorle, arnsacrnt. acIIrom;an (q22;q22) and 1(3;21)(q26.2:q22.1)] and "TCJP(lI5OlTIeIaS IIirlhbIr:Jts may abo be associated WIltIIherapy-related ~ leukaemia other abnormalities such as 1(15;17) (q22;q12) and inv (16)( p 13q22) , The bal- """" Anilmetaboilles: thiopurines, ITl)tOI)Ilenolate, fludarabine An titublJlin agents(usuallyin comblnenco withother agents):vincristine, vinblastine, virdesine, paditaxet, anc ed transtocano ns are generally asso- ci ated with a short latenc y period, most often present as ove rt AMl without a docetaxel pr ec ed ing mverocvsptasnc phase. and128 Acute myeloid leukaerrua and rela ted precursor neoplasms
  • 124. are associated with prior toootsomerase of less than 10% is commonly reported . with balanced translocations genera llyII inhibitor therapy. Cases assoc iated with abno rmalities of have a be tter prognosis, but. except for chromo some 5 and/or 7 and a com ple x those with t(15;17)(q22;q 12) and inv(16)Postulated normal counterpart karyotype ha ve a particularly poo r out- (p 13.1q22) or t( 16;16)(p 13.1;q22). me-Haematopoietic stem c ell. come. with a median survival time ot less dian survival times are shorter than for than one year regard less 0 1 whether they their de novo count erparts 136. 227 , 1886.Prognosis and predictive factors pre sent as overt acute leukaemia or as 2034 .20411 .The prognosis 01t-AML./l-MOS and t-AMU t-MOS 11472, 20261. In contrast to de novo It shou ld be noted that occ asional pa--MDS/M is generally poor. although it PN MOS, some report s have suggested that tients assigned to the category of therapy-is strongly influenced by the associated neither the blast percentage nor subclas- related myeloid neoplasms representkaryotypic abnormality as well as the sification have a significant impact on coincidental disease and would be ex-comorbidity of the underlying malignancy clinical outcome, and the designation of pected to behave like other de novoor disease for which cytotoxic therapy t-AMUt-MOS or t-AMUt-MDS/MPN may disease.waslitialyrequired. CNeratl, 5-year SlJVivaI be more appropriate 11472. 20261. Patients Therapy-related myeloid neoplasms 129
  • 125. Acute myeloid leukaemia, D.A. Arber R D. Brunning L. Peterson J. Thielenot otherwise specified A.Orazi A. Porwil M.M. Le BeauThe c ategory of ac ute myeloid leukaemia, PB smears , and 8 M trep hine b iopsies,not otherwise spec ified (AML. NOS) en- The recommendation s for cl as sif ic ationco mpasses those cas es that do not fulfil are applicable only to specimens obtainedcriteria lor inclusion in one of the p revi - prior to chemoth erapy. It should be notedously desc ribed groups with rec urrent tha t most of the epidemiolo gic data citedgenetic abnormalities, myelodysplasia-re- for each AMl, NOS entity has beenlate d c hanges or tha i are therapy-related . lar gely g athered from studies using theThese tumours are fell 10 be derived from p rior FAB classi fication scheme, and mayhaematopoietic stem cells . The clinical not directly apply to series of patientsrelevanc e of some subgroups 01 AML. classi fied by the WHO sys tem, in whichNOS is of q uestionable significance 169. most patients will be classified into other,21531 bu t they are reta ined in the cl assi fi- more specific entities , and fOf which suf-cation because they define criteria for the ficient epid emiologic d ata is not yet avail-d iagnosis 01 A ML ac ross a diverse mor- able.pholog ic spectrum and include the uniqued iagnostic criteria for ervmroreukaemra.Mutation ana lysis and cytoge netic stud- Acute myeloId leukaemia with