The document defines myelodysplastic syndromes as a group of clonal stem cell diseases characterized by cytopenia, dysplasia in one or more myeloid lineages, ineffective hematopoiesis, recurrent genetic abnormalities, and an increased risk of developing acute myeloid leukemia. It discusses the epidemiology, etiology, pathophysiology, cytogenetics, morphological features, clinical features, WHO classification, differential diagnosis, variants, immunophenotyping, management, and prognosis of MDS. The document provides details on the definition, evaluation, classification, genetic abnormalities, and clinical manifestations of myelodysplastic syndromes.

1. 1
MYELODYSPLASTIC
SYNDROMES
PRESENTER :DR MADHURI REDDY
MODERATOR :DR ANISHA T S

2. 2
CONTENTS
DEFINITION
EPIDEMIOLOGY
ETIOLOGY
PATHOPHYSIOLOGY
CYTOGENETICS IN MDS
MICROSCOPY /MORPHOLOGICAL FEATURES
CLINICAL FEATURES
WHO CLASSIFICATION 2016
DIFFERENTIAL DIAGNOSIS
VARIANTS
IMMUNOPHENOTYPING
MANAGEMENT & PROGNOSIS
PITFALLS
ANCILLARY TECHNIQUES

3. Definition
The myelodysplastic syndromes (MDS) are a group of clonal haematopoietic
stem cell diseases characterized by
● Cytopenia,
● Dysplasia in one or more of the major myeloid lineages,
● Ineffective haematopoiesis,
● Recurrent genetic abnormalities
&
● Increased risk of developing acute myeloid leukaemia (AML)
3

4. 4
The recommended thresholds for cytopenias established in the original
International Prognostic Scoring System (IPSS) for risk stratification
● haemoglobin concentration < 10 g/dL,
● platelet count < 100 x 109/L &
● absolute neutrophil count < 1.8 x 109/L
However, a diagnosis of MDS may still be made in patients
● with milder degrees of anaemia (haemoglobin< 13g/dL in men or <
12g/dL in women)
● or thrombocytopenia (platelets < 150 x 109 /L)
if definitive morphologic &/or cytogenetic findings are present

5. 5
● The morphological hallmark of MDS is dysplasia in one or more
myeloid lineages.
● An increase in myeloblasts in the peripheral blood and/or bone
marrow( blasts < 20 %)
● Recurrent cytogenetic abnormalities are present in 40-50% of cases,
whereas acquired somatic gene mutations are seen in the vast
majority of MDS cases at diagnosis

6. Epidemiology
MDS occurs principally in
●Older adults (median patient age: 70
years)
●Male predominance
The annual incidence is
● 3- 5 cases per I00,000 population
overall (non-age-corrected)
● 20 cases per I00,000 individuals aged
> 70 years
6

7. Etiology  PRIMARY/ DENOVO
 SECONDARY
7

8. 8
● Constitutional genetic disorders
 Down syndrome,
 Trisomy 8 mosaicism
 Familial monosomy 7
● Congenital neutropenia
 Kostmann syndrome
● Dyskeratosis congenita
● Shwachman Diamond syndrome
● Diamond Blackfan syndrome
Inherited factors
● DNA repair defects
 Fanconi’s anemia,
 Ataxia telangiectasia,
 Bloom syndrome
 Xeroderma pigmentosum
● Neurofibromatosis 1
● Germ cell tumors (embryonal
dysgenesis)
● Mutagen detoxification(GSTq1-null)

9. 9
● Senescence
● Mutagen exposure
● Environmental or occupational exposure (e.g.,benzene)
● Tobacco smoking
● Agricultural solvents
● Aplastic anaemia
● PNH
● Polycythemia vera
● Alkylating agents,P32,DNA topoisomerase II inhibitors
Acquired
Acquired factors

10. Pathophysiology
of MDS
ABERRATIONS IN
APOPTOTIC
MECHANISMS
10

11. 11
MDS
Apoptosis
Stem cell
defect
Angioge
-nesis
Epigenet
-ic
Immuno
-logical
Genetic
loss of
signal Molecular
gain of
function
Environ-
mental

12. 12Apoptosis is chiefly brought about by cysteine proteases called caspases
which are activated by
 Receptor mediated extrinsic pathway
 Mitochondrial/intrinsic pathway( Bcl-2 mediated)
APOPTOTIC INDEX
 High in early MDS
 Decreases with onset of AML
Increased apoptosis & proliferation
 Low risk MDS –apoptosis is prominent
 High risk MDS-proliferation is prominent

13. 13
THEORIES OF
PATHOPHYSIOLOGY
INVOLVED IN MDS
DEVELOPMENT
POTENTIAL
TARGETS/COMPONENTS
INVOLVED
OVERALL RESULT OF
ABNORMALITY
Environmental/Aging
Aging Increased BM apoptosis Decreased hematopoietic stem
cell pool
Environmental Exposures Smoking
Radiation
Benzene
Viral Infections
Chemotherapy
Direct Toxicity to hematopoietic
stem cells
Telomere Abnormalities Potential decreased
telomerase and subsequent
telomere shortening
• Impaired ability to renew stem
cell pool.
• Genetic Instability

14. 14
Genetic Alterations
Cytogenetic
Abnormalities
Common Abnormalities:
• 5q- , 20q-
• Y- , Trisomy 8
• 7q-/Monosomy7, 17p Syndrome
• 11q23, 3q
• p53 mutations, RAS mutations
• Complex Cytogenetics
•Typically unbalanced genetic loss
• Numerous theories of tumor
suppressor Loss
• Multi-Hit progression from low
risk MDS to AML
•Genetic Instability
Epigenetic
Modulation
•Hypermethylation
•Acetylation Alterations
Methylation and acetylation
abnormalities lead to silencing of
genes important in cell cycle ,
differentiation, apoptosis &
angiogenesis

15. 15
Altered Bone Marrow
Microenvironment
Altered Bone Marrow
Microenvironment
Upregulation of
cytokines :TNF-α, IFN-
γ,TGF-β, IL-1β, IL-6,IL-11
•Alteration of growth, differentiation,
angiogenesis
•Immune modulation
Alterations in Apoptosis
via Signalling
•Increased TNF-α levels
•FAS: Increased
Apoptosis
•BCL-2 alterations
•Increased apoptosis and proliferation in
early stage MDS leading to hypercellular
marrow with peripheral cytopenias
• Decreased apoptosis and increased
proliferation in later stage MDS leading to
progression to AML
Increased Angiogenesis •Increased VEGF
•Possible Increase : FGF
and EGF ,Angiogenin
Increased Microvessel Density(MVD): role
in pathogenesis not clearly elucidated but
associated with progression to AML

16. 16
Immune
Dysregulation
•T cell Expansion
•B cell alterations
•Increased T cells leading
to potential attack on
hematopoietic stem cells.
•Etiology: Possible chronic
antigenic stimulation
Abnormal
Differentiation
•Cell Cycle Maturation arrest.
•Altered Proliferation.
•Transcription Factors alterations
•Impaired maturation
•Cytopenias
• Progression to leukemia

17. 17
 HSC’s in MDS have premalignant or malignant characteristics with
defective maturation that often leads to uncontrolled proliferation
 Autocrine production of angiogenic molecules –promotes expansion of
leukemic clone .
 Bone marrow neovascularity increases in proportion to marrow blast
cell percentage.
 There is overexpression of VEGF-1/VEGF-2 receptors .
 Clonal chromosomal abnormalities occur in 30-50% of de novo MDS
and in 80-90% of t-MDS.

18. Cytogenetics in
MDS
3 GROUPS OF PATIENTS OF MDS
■ Normal karyotype
■ Balanced chromosomal abnormalities
causing generation of fusion
oncogenes
■ Complex karyotypes (> 3
abnormalities )
18

19. 19
Chromosomal abnormality Frequency
MDS overall Therapy related
UNBALANCED
Gain of chromosome 8 10%
Loss of chromosome 7 or del{7q) 10% 50%
del(5q) 10% 40%
del(20q) 5-8%
Loss of Y chromosome 5% 25-30%
Isochromosome 17q or t(17p) 3-5%
Loss of chromosome 13 or del{13q) 3%
del(11q) 3%
del{12p) or t(12p) 3%
del(9q) 1-2%
idic(X)(q13) 1-2%

20. 20Chromosomal abnormality Frequency
MDS overall Therapy related
BALANCED
t(11 ;16)(q23.3;p13.3) 3%
t(3;21)(q26.2;q22.1) 2%
1(1 ;3)(p36.3;q21.2) 1%
t(2;11)(p21 ;q23.3) 1%
inv(3)(q21.3q26.2) I
t(3;3)(q21.3;q26.2)
1%
t(6;9)(p23;q34.1) 1%

21. 21
CYTOGENETIC ABNORMALITIES AND THEIR ASSOCIATIONS IN MDS
Cytogenetic abnormality Associated with
Del 5q Good prognosis in elderly patients with thrombocytosis and
macrocytic anemia
Del 7q Differentiates hypocellular MDS from aplastic anemia
Monosomy 7 Pediatric MDS-25% cases demonstrate it,JMML (MDS/MPN)
Del 11q Intermediate risk
Del 17p Dysgranulopoesis ,pseudo-Pelger-Huet anomaly with small
vacuolated neutrophils and TP53 mutation,and poor response to
therapy
Monosomy 5 MDS-EB
Del 12p CMML
Trisomy 8 MDS-RS & CMML
11q23 Secondary/therapy related MDS

22. 22
RELATIONSHIP B/W CHROMOSOMAL ABNORMALITIES
& BLOOD/BONE MARROW MORPHOLOGY
Chromosomal abnormality Characteristic morphology
i17q/17p loss Hypolobated neutrophils,abnormal chromatin clumping
3q26 Thrombocytosis
Hypolobated small megakaryocytes
Trisomy 8 Younger patient with less transfusion
dependence,responsive to immunosuppressive therapy
Del 20q Isolated thrombocytopenia with minimal dysplasia
Del 5q Thrombocytosis ,unilobated megakaryocytes,macrocytic
anemia

23. 23
COMMON GENE MUTATIONS IN MDS
Gene mutated Pathway Frequency Prognostic impact
SF3B1* RNA splicing 20-30% Favourable
TET2* DNA methylation 20- 30% Conflicting /neutral
ASXL1* Histone modification 15-20% Adverse
SRSF2* RNA splicing 15% Adverse
DNMT3A* DNA methylation 10% Adverse
RUNX1 Transcription factor 10% Adverse
U2AF1* RNA splicing 5- 10% Adverse
TP53* Tumour suppressor 5-10% Adverse
EZH2 Histone modification 5-10% Adverse
ZRSR2 RNA splicing 5-10% Conflicting /neutral
STAG2 Cohesin complex 5-7% Adverse
IDH1/IDH DNA methylation 2 -5% Conflicting /neutral
CBL* Signalling 5% Adverse
BCOR* Transcription factor 5% Adverse
NRAS Transcription factor 5% Adverse

24. Dysplastic
features in MDS
 DYSERYTHROPOIESIS
 DYSMYELOPOIESIS
 DYSMEGAKARYOPOIESIS
24

25. Morphological manifestations of
dysplasia in MDS
25
● Small / unusually large size
● Nuclear hyposegmentation
(pseudo-Pelger-Huet)
● Nuclear hypersegmentation
● Decreased granules;
agranularity
● Pseudo-Chediak-Higashi
granules
● Dohle bodies
● Auer rods
● Nuclear budding
● Internuclear bridging
● Karyorrhexis
● Multinuclearity
● Megaloblastoid changes
● Ring sideroblasts
● Vacuolization
● Periodic acid-Schiff (PAS)
positivity
DYSMEGAKARYOPOIESISDYSMYELOPOIESISDYSERYTHROPOIESI
S ● Micromegakaryocytes
● Nuclear hypolobation
● Multinucleation

26. 26
DYSPLASIA IN MDS
DYSGRANULOPOESIS
DYSMEGAKARYOPOESIS
Normal
megakaryocyte
Separated
single nuclei
Micro-
megakaryocyte
Small binucleate
megakaryocyte
Round non lobulated
megakaryocyte
Normal
erythroblast
Nuclear bridging
Nuclear
lobulation
Multiple
nuclei
Cytoplasmic
granules
Megaloblastic
changes
Normal neutrophil Pseudo Pelger–
Huet anomaly
Macrocytosis Chromatin
clumping
Hypo-
,agranulated
cytoplasm
Nucleus-cytoplasm
maturation asynchrony

27. Dyserythropoiesis
The nuclei of two
polychromatic erythroid
precursors in the upper
right are connected by a
thin chromatin strand
(internuclear bridging);
The two cells are unequal
in size and the nucleus on
the right is lobed
27

28. 28
Dyserythropoiesis and megaloblastic changes (BM)

29. 29
Nucleated red cell progenitors with multilobated or multiple nuclei (BM)

30. 30
Bone marrow smear shows marked
erythroid hypoplasia, with occasional giant
erythroblasts with dispersed chromatin and
fine cytoplasmic vacuoles
Bone marrow smear from a 47-year-
old man with pancytopenia being
chronically exposed to arsenic; there is
marked dyserythropoiesis.

31. Dysmyelopoesis
(A )Blood smear from a patient on G-CSF, showing a neutrophil with a bilobed
nucleus and increased azurophilic granulation and a Myeloblast (B)
31
A

32. Dysplastic
megakaryocytes
Bone marrow aspirate smear
from a 37-year-old man with
pancytopenia,showing
hypolobated megakaryocytes
& micromegakaryocytes.
32

33. 33
C, Pseudo-Pelger-Hüet cells, neutrophils with
only two nuclear lobes instead of the normal
three to four, are observed at the top and
bottom of this field
D, Megakaryocytes with multiple nuclei instead
of the normal single multilobated nucleus.

34. 34
Large mononuclear megakaryocyte. Micromegakaryocyte

35. PERIPHERAL BLOOD EXAMINATION
Do’s and dont’s
 Differential count of 200 cells
 Buffy coat evaluation in leucopenia
 Slides for the assessment of dysplasia should be made from
freshly obtained specimens; specimens exposed to anticoagulants
for > 2 hours are unsatisfactory
35

36. 36
PERIPHERAL SMEAR
 Dimorphic with Macrocytosis and normochromic RBCs is observed
 Neutropenia in 50% cases
 Pince-nez nuclei along with cytoplasmic hypogranularity in neutrophils is
characteristic.
 Monocytosis ,basophilia,eosinophilia or lymphocytosis may be present
 Thrombocytopenia in 30% cases

37. 37
MEGAKARYOCYTIC SERIES
 Giant platelets
 Hypogranular platelets
 Agranular platelets
ERYTHROID SERIES
 Ovalocytosis
 Macrocytosis
 Elliptocytosis
 Stomatocytes
 Tear drop cells
 Nucleated red cells
 Basophilic stippling
 Howell –Jolly bodies
PERIPHERAL BLOOD FINDINGS
MYELOID SERIES
 Pseudo-Pelger Huet
anomaly
 Auer rods
 Hypogranulation
 Irregular contour of
nuclei
 Hypo and hyper
segmentation of
nuclei
 Ring shaped nuclei

38. BONE MARROW ASPIRATE/BIOPSY
PREREQUISITES IN ASPIRATE /IMPRINT /BIOPSY SMEARS
 Less than 0.5 ml of marrow should be aspirated for morphological assessment to
avoid excessive dilution with peripheral blood cells.
 Minimum of 500 nucleated cells should be counted.
 Blast cells are counted as % of total marrow cells rather than % of non erythroid
cells.
 Minimum of 30 megakaryocytes to be counted.
38

39. 39
BM ASPIRATE/IMPRINT SMEARS
 Hypercellular
 Dysplasia of hematopoetic cell lines
 Blast cells may demonstrate a diminished staining to MPO and SBB
 Megakaryocytes-N/C asynchrony- non lobated immature nuclei with
mature granular cytoplasm
BONE MARROW BIOPSY
 Helps in determining
 Cellularity
 ALIPS
 Reticulin fibrosis
 Megakaryocytic dysplasia
 Lymphoid aggregates
 Hypoplastic MDS

40. 40
MYELOID SERIES
 Defective granulation
 Nuclear hypolobation
 Auer rods in myeloid cells
 Maturation arrest at
myelocyte stage
 Increase in monocytoid cells
 Abnormal localisation of
immature precursors(ALIP)
 Pseudo Chediak Higashi
granules
 Irregular nuclear
hypersegmentation
ERYTHROID SERIES
 Megaloblasts
 Nuclear bridging
 Ring sideroblasts
 Nuclear fragments
 Multinucleation
 Karyorrhexis
 Cytoplasmic
vacuolation
 PAS stain positive
 Nuclear hyperlobation
 Multinuclearity
BONE MARROW FINDINGS
MEGAKARYOCYTIC SERIES
 Micromegakaryocytes
 Hypogranulation of
megakaryocytes
 Multiple small nuclei of
megakaryocytes
 Nuclear hypolobation
 Vacuolated megakaryocytes

41. 41ALIPS
 In health,
• immature myeloid precursors are seen close to bony trabeculae and
around blood vessels,
• whereas developing erythroid cells and megakaryocytes are seen in
intertrabecular spaces.
 In MDS,
• myeloid precursors are displaced from trabecular margins and small
clusters of myeloblasts and promyelocytes are sometimes seen in
intertrabecular spaces.
• The clusters are called ALIPS (abnormal localization of immature
precursors) and may develop due to autocrine production of vascular
endothelial growth factor.

42. 42
Marrow trephine stained for neutrophil elastase
showing a ‘true ALIP

43. Clinical features
 Anemia (about one third of patients are dependent on red blood cell
transfusions at diagnosis )
 Neutropenia and/or thrombocytopenia are less common;
 Organomegaly(infrequent).
 Infections (bacterial pneumonias and skin abscesses)
43

44. WHO
CLASSIFICATION
OF MDS -2016
The MDS category encompasses several
distinct subtypes, which are defined by
the
♠ number of cytopenias at presentation,
♠ the number of myeloid lineages
manifesting dysplasia,
♠ the presence of ring sideroblasts,
♠ and the blast percentages in the blood
and bone marrow
In the current classification, only one
cytogenetic abnormality, del(5q), is used
in the definition of a specific MDS subtype
44

45. 45
Entity name Number of
dysplastic
changes
Number of
cytopenias
Ring sideroblasts
as % of marrow
erythroid
elements
Bone marrow
and peripheral
blood blasts
Cytogenetics by
conventional karyotype
analysis
MDS-SLD 1 1-2 <15%/<5% BM<5%,
PB<1%
no Auer rods
Any,unless fulfills all
criteria for MDS with
isolated del(5q)
MDS-MLD 2-3 1-3 <15%/<5% BM<5%,
PB<1%
no Auer rods
Any,unless fulfills all
criteria for MDS with
isolated del(5q)
MDS-RS
MDS-RS-
SLD
MDS-RS-
MLD
1
2-3
1-2
1-3
≥15%/≥5%
≥15%/≥5%
BM<5%,
PB<1%
no Auer rods
BM<5%,
PB<1%
no Auer rods
Any,unless fulfills all
criteria for MDS with
isolated del(5q)
Any,unless fulfills all
criteria for MDS with
isolated del(5q)

46. 46
Entity name Number of
dysplastic
changes
Number
of
cytope-
nias
Ring sideroblasts
as % of marrow
erythroid
elements
Bone marrow
and peripheral
blood blasts
Cytogenetics by
conventional
karyotype analysis
MDS with
isolated
del(5q
1-3 1-2 None or any BM<5%,
PB<1%,
No Auer rods
Del(5q)alone or with 1
additional
abnormality,except
loss of chromosome 7
or del(7q)
MDS-EB
MDS-EB-1
MDS-EB-2
1-3
1-3
1-3
1-3
None or any
None or any
BM 5-9% or PB
2-4%,BM <10%
and PB <5%,
No Auer rods
BM 10- 19% or
PB 5- 19% or
Auer rods,
BM & PB<20%
Any
Any

47. 47
Entity name Number of
dysplastic
changes
Number of
cytopenias
Ring
sideroblasts as
% of marrow
erythroid
elements
Bone marrow &
peripheral blood
blasts
Cytogenetics by
conventional
karyotype analysis
MDS-U
With 1% blood
blasts
With SLD &
pancytopenia
Based on
defining
abnormality
1-3
1
0
1-3
1-3
1-3
None or any
None or any
<15%
BM<5%,
PB=1%
No auer rods
BM<5%,
PB=1%
No auer rods
BM<5%,
PB=1%,
No auer rods
Any
Any
MDS defining
abnormality

48. MDS with single lineage dysplasia
 Cases that present with
 unexplained cytopenia or bicytopenia,
 10% dysplastic cells in one myeloid lineage.
 The presenting lineage dysplasia and cytopenias(s) should be noted in the
diagnostic conclusion.
 If SF3B1 mutation status is unknown, cases with 5- 14% ring sideroblasts and
single lineage dysplasia be classified as MDS-SLD.
48

49. 49
Myelodysplastic syndrome with
single lineage dysplasia.
 Bone marrow smear from a 27-
year-old man shows a
dysplastic megakaryocyte.
 There is asynchronous nuclear-
cytoplasmic maturation, with
well-granulated cytoplasm and
a non-lobated immature
nucleus

50. 50
MDS-SLD
 Peripheral blood smear from a
56-year-old man shows
granulocytic dysplasia.
 The neutrophil in the lower left
is dysplastic,
 with moderately
hypogranular cytoplasm
and occasional Dohle
bodies;
 the nucleus shows retarded
segmentation.

51. 51DIFFICULT DIFFERENTIAL DIAGNOSES IN MDS-SLD
 Idiopathic cytopenia of undetermined significance
 Persistent cytopenia without dysplasia and without one of the
specific cytogenetic abnormality(presumptive evidence of MDS)
 Hematologic and cytogenetic status should be monitored.
 MDS-MLD
 MDS-RS-SLD

52. MDS with ring sideroblasts
 MDS with ring sideroblasts is characterized by
 cytopenias
 morphological dysplasia
 ring sideroblasts constituting ≥ 15% of the bone marrow erythroid
precursors.
 SF3B1 mutation in most cases, (≥5% marrow ring sideroblasts is diagnostic
in such cases)
52

53. 53
 Two categories of MDS-RS are recognized
 MDS-RS with single lineage dysplasia
 MDS-RS with multiple lineage dysplasia
 MDS with ring sideroblasts & single lineage dysplasia (MDS-RS-SLD)
• anaemia,
• dysplasia is limited to the erythroid lineage.
 MDS with ring sideroblasts and multilineage dysplasia (MDS-RS-MLD)
• Any number of cytopenias,
• Significant dysplasia in 2 or 3 haematopoietic lineages.

54. 54
 Clinical features
• Hepatomegaly
• splenomegaly
• Macrocytic/Normocytic normochromic anaemia.
 Peripheral blood
• Dimorphic population of red blood cells
 Bone marrow aspirate
 MDS-RS-SLD
• Increase in erythroid precursors with erythroid lineage dysplasia,( nuclear
segmentation & megaloblastoid features)
• Granulocytes/Megakaryocytes -no significant dysplasia (< 10% dysplastic forms).
• Haemosiderin-laden macrophages are abundant.
• Myeloblasts constitute < 5% of the nucleated bone marrow cells

55. 55Contd…….
 MDS-RS-MLD
• Erythroid lineage dysplasia
• Ringed sideroblasts
• Significant dysplasia (≥ 10% dysplastic forms) in 1 or 2 non-erythroid
lineages.
• Iron stained aspirate smears - ≥ 15% (or ≥5% if SF3B1 mutation
present)of the red blood cell precursors are ring sideroblats
 Bone marrow biopsy
• Normocellular to markedly hypercellular with marked erythroid proliferation.

56. 56
Heterozygous mutations in SF3B1
SF3B1 encodes core component of U2snRNP spliceosome
Altered splicing of mitochondrial iron transporter gene
ABCB7 & other mitochondrial metabolism genes,
Ineffective erythropoiesis & ring sideroblasts that
characterize MDS-RS
GENETICS IN MDS-RS

57. 57DIFFERENTIAL DIAGNOSIS
 AML
 MDS with excess blasts
 MDS with isolated del(5q)
 Non-neoplastic causes of ring sideroblasts,
 Alcohol,
 Toxins (e.g. lead and benzene),
 Drugs (e.g. isoniazid),
 Copper deficiency (which may be induced by zinc administration),
 Congenital sideroblastic anaemia

58. 58
A Blood smear with dimorphic red
blood cells and macrocytes..
B Bone marrow aspirate smear showing
marked erythroid proliferation, with a
dysplastic binucleated form

59. 59
Iron stain of bone marrow aspirate showing numerous ring sideroblasts

60. 60
MDS –RS
BM aspirate showing
numerous ring sideroblasts,
several of which can be seen
to have defectively
haemoglobinized
cytoplasm.
Perls ’ stain × 100.

61. 61
BM aspirate,
WHO MDS-RS category,
showing five erythroblasts,
two of which show
defectively
haemoglobinized,
heavily granulated
cytoplasm.

62. MDS with multilineage dysplasia
 MDS characterized by
 one or more cytopenias and
 dysplastic changes in two or more of the myeloid lineages (erythroid,
granulocytic, and megakaryocytic)
 Differential diagnosis
 MDS-RS-MLD
 MDS-U
62

63. 63
MDS with multilineage
dysplasia and complex
cytogenetic abnormalities.
Bone marrow section
from a 37-year-old man
with pancytopenia
showing markedly
increased
megakaryocytes, many
with
dysplastic features.

64. 64
MDS-MLD
 Bone marrow smear
shows evidence of
dysplasia in both the
erythroid precursors
and the myeloid
precursors;

65. 65
MDS-MLD showing a binucleate micromegakaryocyte with its
budding platelets.

66. MDS with excess blasts
 MDS characterized by
 5-19% myeloblasts in the bone marrow or
 2- 19% blasts in the peripheral blood
 but < 20% blasts in both bone marrow and blood
 ALIP is a common finding
 Divided into 2 subcategories
 MDS with excess blasts 1 (MDS-EB-1)
 MDS with excess blasts 2 (MDS-EB-2)
66

67. 67MDS with excess blasts 1 (MDS-EB-1)
 5-9% blasts in the bone marrow or
 2-4% blasts in the peripheral blood
 (but < 10% blasts in the bone marrow and <5% blasts in the blood)
MDS with excess blasts 2 (MDS-EB-2)
 10-19% blasts in the bone marrow or
 5- 19% blasts in the peripheral blood
 The presence of Auer rods in blasts designates any MDS case as MDS-EB-2
irrespective of the blast percentage
MDS with excess blasts and erythroid predominance
MDS with excess blasts and fibrosis

68. 68
MDS with excess blasts and fibrosis
 In about 15% of cases of MDS, the bone marrow shows a significant degree of
reticulin fibrosis (grade 2 or 3 according to the WHO grading system).
 They have been termed MDS with fibrosis (MDS-F) , and most belong to the
MDS-EB category (MDS-EB-F).
Differential diagnosis
 Therapy-related myeloid neoplasms,
 Myeloproliferative neoplasms,
 Lymphoid neoplasms
 Various reactive conditions(infections and autoimmune disorders)

69. 69
Bone marrow section from a case of MDS-
EB-1 containing a focus of immature myeloid
precursors
Bone marrow biopsy from a case of MDS-EB-
2 showing a focus of immature cells,most of
which stain positively for CD34

70. MDS with isolated del(5q)
 MDS characterized by anaemia (with or without other cytopenias and/or
thrombocytosis)
&
 the cytogenetic abnormality del(5q) occurs either in isolation or with one
other cytogenetic abnormality, other than monosomy 7 or del(7q).
 Myeloblasts constitute
 < 5% of the nucleated bone marrow cells and
 <1% of the peripheral blood leukocytes.
 Auer rods are absent.
70

71. 71
 Bone marrow
♠ Hypercellular / normocellular
♠ Erythroid hypoplasia
♠ Megakaryocytes - increased in number with dysplastic features
♠ Erythroid/Myeloid lineage -dysplasia is less pronounced
♠ The blast percentage is < 5%
♠ Ring sideroblasts may be present
 Peripheral blood
♠ The blast percentage is < 1%

72. 72
 The presumed etiology is loss of a tumour suppressor gene or genes in the minimally
deleted region (5q33.1)
 The size of the deletion and the breakpoints vary, but bands q31-q33 are invariably
deleted.
 Haploinsufficiency of :
♠ RPS14
• Encodes a ribosomal structural protein→ p53 pathway activation .
♠ miR-145 and miR-146a
• megakaryocyte abnormalities
• thrombocytosis .
♠ CSNK1A 1 (encoding casein kinase 1A1)
• WNT/beta-catenin pathway deregulation - proliferation of del(5q) clone
♠ APC (another WNT pathway regulator) and EGR1
DISEASE PATHOGENESIS

73. 73
A Bone marrow section showing
numerous megakaryocytes of various
sizes, several with non-lobated nuclei.
B Bone marrow aspirate smear
showing two megakaryocytes with
non-lobated, rounded nuclei.

74. 74
Bone marrow aspirate showing a megakaryocyte of normal
size with a hypolobated nucleus-MDS del(5q)

75. Myelodysplastic syndrome, unclassifiable
The diagnosis of MDS-U can be made in any of the following settings:
I. There are findings that would otherwise suggest classification as other types
but with
 1% blasts in the peripheral blood
 on at least two separate occasions
II. There are findings that would otherwise suggest classification as
 MDS - SLD
 MDS- RS-SLD with PANCYTOPENIA
 MDS with isolated del(5q)
75

76. 76III. There is
 persistent cytopenia
 < 2% blasts in the blood
 < 5% in the bone marrow,
 no significant(< 10%) unequivocal dysplasia in any myeloid lineage,
&
 the presence of a cytogenetic abnormality considered presumptive
evidence of MDS
If characteristics of a specific subtype of MDS develop later in the course of the
disease, the case should be reclassified accordingly.

77. Refractory cytopenia of childhood
♠ It is a provisional MDS entity characterized by persistent cytopenia, with <5%
blasts in the bone marrow and < 2% blasts in the peripheral blood
♠ About 80% of children with RCC show considerable hypocellularity of the
bone marrow
♠ Therefore should be differentiated from aplastic anemia and inherited bone
marrow failure disorders
77

78. 78
Specimen Erythropoiesis Granulopoiesis Megakaryopoiesis
Bone marrow
aspirate
Dysplastic changes and/or
megaloblastoid changes
Dysplastic changes in
granulocytic precursors
and neutrophils;
<5% blasts
Unequivocal micromega
karyocytes; other
dysplastic changes in
variable numbers
Bone marrow
biopsy
A few clusters of ≥20%
erythroid precursors.
Arrest in maturation,with
increased number of
proerythroblasts.
Increased number of
mitoses.
No minimal diagnostic
criteria
Unequivocal
micromegakaryocytes;
IHC is obligatory
(CD61,CD41);other
dysplastic changes in
variable numbers
Peripheral blood Dysplastic changes in
neutrophils
Minimal diagnostic criteria for refractory cytopenia of childhood

79. 79
Bone marrow biopsy shows hypoplasia and patchy distribution
of hematopoesis in particular erythropoiesis

80. 80
Bone marrow biopsy -CD61 immunohistochemistry shows
dysplasia of megakaryocytes, with small, non-lobated nuclei or
separated nuclei

81. 81
Criteria Refractory cytopenia of childhood Aplastic anemia in children
BM BIOPSY BM ASPIRATE BM BIOPSY BM ASPIRATE
Erythropoie-
sis
Patchy distribution
Left shift
Increased mitosis
Nuclear
segmentation
Multinuclearity
Megaloblastoid
changes
Absent or single
small focus;
<10 cells with
maturation
Absent or very few
cells,without
dysplasia or
megaloblastoid
change
Granulopoie-
sis
Marked decrease
Left shift
Pseudo-Pelger-Huet
anomaly
Agranularity/hypogra
nularity of cytoplasm
N/C maturation
defects
Absent or markedly
decreased ,with
very few small foci
with maturation
Few maturing
cells,with no
dysplasia
Megakaryo-
poiesis
Marked decrease or
aplasia
Dysplastic changes
Micromegakaryocyte
s
Micromegakaryocyte
s
Multiple separated
nuclei
Small round nuclei
Absent or very few
non dysplastic
megakaryocytes
Absent or few non
dysplastic
megakaryocytes
COMPARISON OF THE MORPHOLOGICAL CRITERIA FOR HYPOPLASTIC REFRACTORY
CYTOPENIA OF CHILDHOOD AND APLASTIC ANAEMIA IN CHILDREN

82. 82
Criteria Refractory cytopenia of childhood Aplastic anemia in children
BM BIOPSY BM ASPIRATE BM BIOPSY BM ASPIRATE
Lymphocytes May be increased
focally or
dispersed
May be increased May be increased
focally or
dispersed
May be increased
CD34+ precursor
cells
No increase No increase
KIT+ (CD117+)
precursor cells
No increase No increase
KIT+ (CD117+)
mast cells
Slightly increased Slightly increased

83. 83DIFFERENTIAL DIAGNOSIS
 Infection (e.g. cytomegalovirus, herpesviruses, parvovirus 819,
visceral leishmaniasis)
 Vitamin deficiency (e.g. deficiency of vitamin B12, folate, vitamin E)
 Metabolic disorders (e.g. mevalonate kinase deficiency)
 Rheumatological disease
 Systemic lupus erythematosus
 Autoimmune lymphoproliferative disorders (e.g. FAS deficiency)
 Mitochondrial DNA deletions (e.g. Pearson syndrome)
 Inherited bone marrow failure disorders (e.g. Fanconi anaemia, dyskeratosis congenita,
Shwachman-Diamond syndrome, amegakaryocytic thrombocytopenia, thrombocytopenia
with absent radii, radioulnar synostosis, Seckel syndrome)
 Paroxysmal nocturnal haemoglobinuria
 Acquired aplastic anaemia during haematological recovery during or after
immunosuppression

84. 84
Aplastic anaemia:
 Bone marrow biopsy
shows adipocytosis of
bone marrow spaces;
 the few scattered cells
are mainly
lymphocytes, plasma
cells
macrophages,mast
cells and occasional
mature myeloid cells.

85. 85
RCC :Bone marrow aspirate smear
showing abnormal nuclear segmentation
of an erythropoietic precursor cell and a
small megakaryocyte with a bilobed
nucleus.
RCC : Bone marrow biopsy showing a
cluster of proerythroblasts without
maturation.

86. Differntial diagnosis
 Vit B12 & folic acid deficiency
 Exposure to arsenic and other heavy metals
 Congenital dyserythropoetic anemias
 Paroxysmal nocturnal hemoglobinuria
 HIV infection
 Parvo virus B 19 infection
 G-CSF therapy
86

87. 87
 Hypoplastic AML
 MDS/MPN disorders
 AML-therapy related and AML in the elderly
 Primary myelofibrosis
 Accelerated phase of CML and other MPNs
 Myelocathexis
 Pelger –Huet anomaly
 Hereditary sideroblastic anemia
 Thiamine responsive anemia
 Giant platelet syndromes
Hematological disorders associated with myelodysplasia

88. 88
 Advanced age
 Medications
 Heavy metal intoxication
 Cigarette smoking
 Infections
 Metastatic cancer deposits bone marrow
 Exposure to aromatic hydrocarbons
 Autoimmune disorders
Acquired conditions associated with non
clonal myelodysplasia

89. Variants of MDS
 HYPOCELLULAR MDS
 SECONDARY /THERAPY RELATED MDS
 MDS-EO
 MDS WITH MARROW FIBROSIS
 FAMILIAL MDS (MYELOID NEOPLASMS WITH GERMLINE PREDISPOSITION)
89

90. 90
Secondary/therapy related
 Secondary
♠ Bm biopsy shows increased reticulin, stromal edema,gelatinous
marrow transformation
♠ Necrosis of bone marrow
♠ Trilineage dyspoiesis
♠ 10 years younger age of presentation compared to primary
♠ Mostly of MDS-EB type
 Therapy related
♠ MDS occurring after many years of alkylating drug intake associated
with del 7q
♠ MDS after > 2 years of use of topoisomerase ii inhibitors

91. 91
MDS-f
♠ Diffuse coarse reticulin fibrosis ,
with or without
♠ Concomitant collagenisation
♠ Dysplasia in atleast 2 of the cell lineages
♠ Differential diagnosis
 AML –MLD
 Primary myelofibrosis
 CML in accelerated/blastic phase with marrow fibrosis
MDS-Eo
♠ Clonal eosinophilia showing hyposegmented and dysplastic eosinophils

92. 92
Familial MDS
 Families with > 2 cases of
♠ MDS
♠ acute leukemia
♠ unexplained cytopenias
♠ cases with organ manifestations fitting into category of hereditary malignancy
myeloid syndrome(HMMS) should be screened for familial MDS
 Mutations studied are
♠ Germline biallelic CEBPA
♠ Germline GATA2(childhood)
♠ Germline RUNX1,ANKRD26 & ETV6
♠ Germline DDX41(elderly)
♠ Cases of bone marrow failure syndrome,telomere biology disorders,NF1 & noonan
syndrome

93. 93
CLONAL HEMATOPOIESIS OF INDETERMINATE POTENTIAL(CHIP)
 Healthy older people with somatic MDS type mutations in hematopoietic
cells like
♠ DNMT3A
♠ TET2
♠ ASLX1
♠ TP53
♠ JAK2
♠ SF3B1
 High risk of development of hematologic malignancy
 Many of them do not develop MDS after many years of follow up
 Therefore current use of mutations in isolation to diagnose MDS may not
be used

94. Immunophenotyping
 Delineating CD34+ cells and further immunophenotyping to study
abnormal phenotypes of CD34+ cells.
 Aberrant maturation patterns in granulopoiesis can predict morphological
dysplasia.
 An emerging pathological population of CD34 or CD117 cells in low grade
MDS could sugge.st evolution of disease
94

95. 95
ABERRANT PHENOTYPE OF BLASTS IN MDS
OVEREXPRESSION OF CD34,CD117,CD38
DIM EXPRESSION OF CD34,CD38,CD4
ABNORMAL EXPRESSION OF CD4,CD11b,CD15,CD65
LACK/ABERRANTLY DIM CD13,CD33,HLA-DR
CROSS LINEAGE EXPRESSION IN
MYELOID BLASTS
CD2,CD5,CD7,CD19,CD56,TdT

96. 96
Evaluation of suspected MDS
HISTORY
• Prior exposure to chemotherapy/radiation
• Recurrent infections,bleeding/bruising
EXAMINATION
• Pallor/bruising
• Splenomegaly
BLOOD COUNTS
Hb, TLC, platelet count, reticulocyte count
BLOOD FILM
Macrocytosis, cytopenia(s), neutrophilia, monocytosis, pseudo-Pelger-Huet
anomaly, hypogranular neutrophils
BONE MARROW ASPIRATE/IMPRINT SMEARS,IRON STAIN ON BM ASPIRATE
BONE MARROW TREPHINE BIOPSY,CD34,CD41/61 IHC
IMMUNOPHENOTYPING OF BONE MARROW
BONE MARROW CYTOGENETIC ANALYSIS

97. 97EXCLUSION OF REACTIVE CAUSES OF DYSPLASIA
• Megaloblastic anemia
• HIV infection
• Recent cytotoxic therapy
• Alcoholism
• Severe intercurrent illness
BIOCHEMICAL TESTS
• S.Iron
• S.LDH
• TSH
• Red cell folate
• S.Vit B12
OTHER TESTS
• Viral markers including HIV,Parvovirus B19
• Autoimmune diseases workup
• FLAER for PNH

98. Management
 Only hematopoietic stem cell transplantation offers cure
 MDS is refractory to cytotoxic chemotherapy regimens
 Other new drugs recently approved to
♠ Increase blood counts
♠ Decrease progression to leukemia
♠ Increase survival
98

99. 99
 Epigenetic modifiers
♠ Azacytidine
♠ Decitabine
Both can cause myelosuppression worsening the condition
 Lenalidoamide
♠ More favourable toxicity profile
♠ Reverses anemia
 Immunosuppressive therapy
 ATG
 CYCLOSPORINE
 Anti-CD52 monoclonal antibody
 Alemtuzumab
 Hematopoietic growth factors
 Erythropoietin
 G-CSF
Improve blood counts
Improve Hb in those with low serum Epo

100. 100
Prognostic subgroup Defining cytogenetlc abnormalities
Very good Loss of Y chromosome
de1(11q)
Good Normal
del(5q)
de1(12p)
del(20q)
Double, including del(5q)
Intermediate del(7q)
Gain of chromosome 8
Gain of chromosome 19
lsochromosome 17q
Single or double abnormalities
not specified in other
subgroups
Two or more independent
non-complex clones
The Comprehensive Cytogenetic Scoring System (CCSS)
for myelodysplastic syndromes

101. 101
Prognostic subgroup Defining cytogenetlc abnormalities
Poor Loss of chromosome 7
inv(3), t(3q) or del(3q)
Double including loss of chromosome
7 or del(7q)
complex (3 abnormalities)
Very poor Complex (> 3 abnormalities)
CCSS contd…

102. 102
PROGNOSTIC VALUE SCORE VALUES
0 0.5 1 1.5 2 3 4
Karyotype(CCSS
group)
Very good - Good - Intermed-
iate
Poor Very poor
Bone marrow blast
percentage
≤ 2% - >2%to<
5%
- 5-10% >10% -
Hemoglobin
concentration(g/dL)
≥10 - 8 to <10 <8 - - -
Platelets (x109 /L) ≥ 100 50
to<100
<50 - - - -
Absolute neutrophil
count (x109 /L)
≥0.8 <0.8 - - - - -
The Revised International Prognostic Scoring System (IPSS-R)
score values for myelodysplastic syndromes

103. 103
Five risk groups are defined, on the basis of the total score of the
parameters listed above:
 Very low: ≤ 1.5
 Low: > 1.5 to 3
 Intermediate:>3 to 4.5
 High:>4.5 to 6
 Very high:>6

104. 104
Adverse prognostic factors in MDS
Clinical
Therapy-related MDS
Blood
Severe cytopenias
Raised LDH or β2-microglobulin
Marrow morphology
Increased blasts
Trilineage dysplasia
Presence of ALIPS
Immunophenotype
CD7-positive blasts
In vitro colony growth
Leukaemic growth pattern
Chromosome abnormalities
Loss of chromosome 5 or 7
Deletion of chromosome 3q, 5q
(excluding 5q syndrome), 7q, 17p
Structural abnormality of
chromosome 11q23
Complex chromosome abnormalities
Karyotypic evolution
Genetic/epigenetic abnormalities
P53, RAS mutations
Overexpression of WT1
p15 hypermethylation
Telomere shortening
Gene expression profile

105. 105
Hypothetical model of evolution patterns in patients with MDS,
based on growth advantage instability of the malignant clone
Clonesize
Time
Clinical
diagnosis
of AML
Group A
 Stable course
 The majority were ALIP negative
 Additional chromosome abnormalities were
rare
Group C
 Gradual increase in the percentage of marrow
blasts
 ALIP-positive at diagnosis
 Rarely showed karyotypic evolution.
 They frequently succumbed to infections or
haemorrhagic complications with or without
evolution to acute leukaemia.

106. 106
Group B or D
 A rapid increase in blast cells
 Majority of these patients
already had an abnormal
karyotype at presentation
 Most were ALIP positive
 The sudden increase in blasts
was frequently accompanied by
additional chromosomal
abnormalities
Clonesize
Time
Clinical
diagnosis
of AML

107. Problems and pitfalls in the diagnosis
of myelodysplastic syndromes
107
 Diagnostic errors can result from a failure to assess clinical features, peripheral
blood and bone marrow cytology, bone marrow histology and the results of
cytogenetic analysis in all cases.
 A careful clinical assessment is essential, in order to exclude relevant systemic illness
and exposure to drugs, alcohol, heavy metals and growth factors.
 Important pitfalls are relevant drug exposure that has not been disclosed to the
pathologist and unexpected HIV positivity.

108. 108
 Dyserythropoiesis
• Congenital dyserythropoietic anaemias
• Thalassaemic conditions
 Megaloblastic erythropoiesis
• Vitamin B12 and folic acid deficiency
• Drugs interfering with DNA synthesis
 Sideroblastic erythropoiesis
• Secondary to drugs or heavy metals ,
• Copper deficiency
• Mitochondrial cytopathies
• Thiamine - responsive anaemia with diabetes mellitus and sensorineural
deafness.
• Erythropoietic protoporphyria

109. 109
 Differentiating hypoplastic MDS from aplastic anemia and hypoplastic
AML
• Immunophenotyping (IHC>ICC>FCM)
• Good quality sections of trephine biopsy specimens.
• Increased reticulin deposition and dysplastic megakaryocytes.
• Percentage of blasts
 ALIPs vs Immature erythroid cells
 Lymphoid aggregates in MDS vs Non-Hodgkin lymphoma
 MDS with isolated thrombocytopenia vs autoimmune
thrombocytopenic purpura.

110. 110
BM trephine biopsy
section from a HIV - positive
patient taking a high dose of
zidovudine.
The patient had megaloblastic
erythropoiesis and a cluster of
early
megaloblasts was confused with
ALIP;
the linear nucleoli of the
megaloblasts is a clue to their
true nature.

111. 111
BM trephine biopsy
section from a patient with
MDS-RS
showing large sheets of
dysplastic erythroid cells
separated by dilated
sinusoids;
the growth pattern
appears so cohesive that the
appearance could be
confused with infiltration by
carcinoma cells.

112. 112
BM trephine biopsy
section from a patient
with low grade T - cell
lymphoma with
secondary
myelodysplasia;
small hypolobated
megakaryocytes are
apparent.

113. 113
BM trephine biopsy sections from a patient with hypoplastic MDS –EB
(a) showing a disorganized marrow of low cellularity,
(b) at higher power it is apparent that blast cells are increased

114. 114
Interrelationship between Aplastic anaemia, Myelodysplasia,
Paroxysmal nocturnal haemaglobinuria and T-cell large
granulocytic leukaemia

115. Ancillary techniques
 Conventional karyotyping
 FISH
 Gene sequencing
 Sanger’s sequencing
 Next generation sequencing(NGS)
 SNP array
115

116. 116
KARYOTYPING
 Bone marrow karyotyping .
 Bone marrow aspiration in heparin is the preferred sample.
 20 metaphases should be studied
 Denovo MDS-40-60% cases
 Therapy related -MDS-90% cases
FISH
 More sensitive than G banding
 Materials -Bone marrow, blood smear ,marrow biopsy, touch smears ,cytospin
preparations
 CLONAL ON CYTOGENETICS :when 2 cells show same addition or structural abnormality
or 3 cells with loss of same chromosome
 CLONAL ON FISH: any abnormality after the validation of the probe and establishment of
normal range
Chromosomal
abnormalities

117. 117
Gene sequencing
Genes detected by NGS IN Hematolgic neoplasms
 ABL1
 HRAS
 KRAS
 ALK
 IDH1
 NOTCH1
 BRAF
SNP array detects microdeletions
 JAK2
 NPM1
 FLT3
 IDH2
 PTPN11
 KDR
 TP53

118. 118
1. Chapter 13. Diseases of White Blood Cells, Lymph Nodes, Spleen,and Thymus. Robbins and Cotran
Pathologic Basis of Disease.9th edition :614-615
2. Chapter 4. Mixed phenotype acute leukaemia, the myelodysplastic syndromes and histiocytic
neoplasms. Barbara J. B, David M. C, Bridget S. W . Bone marrow pathology. Fourth edition: 166-238
3. Chapter 6.Myelodysplastic syndromes. WHO Classification of Tumours of Haematopoietic and
Lymphoid Tissues. Revised 4th edition : 95-120
4. David G.O, Sally B.K .Chapter 40.The myelodysplastic syndromes. Hoffbrand A.V, Catovsky D,
Edward G.D. Postgraduate Haematology.5th edition :662-680
5. Chapter 25 .Myelodysplastic Syndrome. McKenzie B.S, Williams J.L. Clinical Laboratory
Hematology.3rd edition :511-531
6. Manero G.G. Chapter 79.The Myelodysplastic syndromes. Greer P.J et al. Wintrobe’s Clinical
Hematology.13th edition :1673-1687
7. Young N.S. Chapter 130.Bone Marrow Failure Syndromes including Aplastic Anemia and
Myelodysplasia. Harrison T.R , Wintrobe M.M et al. Harrison’s principles of internal medicine.19th
edition :662-672
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