Immunohistochemistry of MALToma, H. pylori identification and eradication Department of histopathology Medanta The Medicity Gurgaon India

1. DIAGNOSIS AND THERAPY OF
GI MALT LYMPHOMA
PRESENTER: Dr Krati Agrawal
MODERATOR: Dr Ritesh Sachdev

2. Overview
I. Lymphatic system
II. What is MALT?
III. Histology
IV. Introduction to MALT Lymphomas
V. Diagnosis
VI. Differential diagnosis
VII. IPSID
VIII. Treatment modality
IX. Assessment of post eradication biopsies
X. Conclusion
XI. References

3. Lymphatic System
I. Primary lymphoid organs:
1. Bone marrow
2. Thymus
II. Secondary lymphoid organs:
1. Spleen
2. Lymph node
3. MALT

4. MALT: Mucosa Associated Lymphoid Tissue
• GALT: Gut associated lymphoid tissue
• BALT: Bronchus associated lymphoid tissue
• NALT: Nasal associated lymphoid tissue
• CALT: Conjunctival associated lymphoid tissue
• O-MALT: Organised- mucosa associated lymphoid tissue(tonsils)
• L-ALT: Larynx associated lymphoid tissue
• SALT: Skin associated lymphoid tissue

5. Induction of mucosal immunity

6. Histology of MALT
• Lymphoid follicle occupy full thickness of the mucosa
• Mantle zone: broader in the subepithelium
• Marginal zone: This zone is broader in the luminal aspect reaching up
to the epithelium
• Marginal zone B cells form lymphoepithelium
• Area around the follicles contains T cells, plasma cells and accessory
cells

7. HISTOLOGY of Peyer’s Patch

8. Function of MALT
• The epithelium in contact with the lymphoid tissue is specialised to
facilitate the contact of antigens with cells of the immune system.
• The epithelium appears columnar and contains cells with deeply
invaginated basal surfaces - microfold cells or M-cells.
• Immune system cells can enter these invaginations (intraepithelial
pockets) where they are exposed to materials which have been
endocytosed by the epithelial cells and then released into the
invaginations

9. MALT LYMPHOMA

10. Classification
• Nodal
• Extra-nodal
• Splenic

11. Extra-nodal Marginal Zone Lymphoma/MALT
Lymphoma
• Definition: Morphologically heterogeneous B cells including marginal
zone cells, monocytoid cells, small lymphocytes, centrocyte like and
plasmacytoid cells.
• Sites: GI tract, Salivary gland, Thyroid, Ocular adnexa and lung

12. Etiology
• Infection: H. pylori
H. helmenii(gastric)
Chlamydia psittaci(ocular)
Campylobacter jejuni(IPSID)
Borellia burgdorferi(cutaneous)
• Autoimmune diseases: Sjogren syndrome or lymphoepithelial
sialadenitis(salivary gland)
Hashimoto thyroiditis(thyroid)

13. Histomorphology
• Definition: Morphologically heterogeneous B cells
including marginal zone cells, monocytoid cells,
small lymphocytes, centrocyte like and plasmacytoid
cells.
• Infiltrate into the interfollicular region
• Infiltration of the glands and crypts with
architectural destruction resulting in
lymphoepithelial lesion
• Clusters of three or more cytologically atypical cells
in the epithelium
• Eosinophilic degeneration of the epithelium
• Neoplastic cells infiltrate the follicles
• Plasma cell differentiation is seen in 1/3rd cases
B/7899/12

14. • Pulmonary MALT Lymphoma:
 Single or multiple nodules
 Presents with cough and dyspnoea
 Lymphangitic pattern of infiltration,
spreading along bronchovascular
bundles, interlobular septa and
visceral pleura with replacement of
pulmonary parenchyma
lymphoepithelial lesion
A B

15. • Salivary Gland MALT
Lymphoma:
 Atrophic acinar
tissue infiltrated by
small lymphocytes and
plasma cells
 Epimyoepithelial
islands
 Haloes or collars
of pale monocytoid B
cells around these
islands
A B

16. GI LYMPHOMAS

17. GI Lymphomas
• Stomach is the most common involved site(60-75%)
• Small bowel>ileocaecal region>rectum
• 3-5% of all malignant tumours
• 90% of the primary gastrointestinal lymphomas are of B cell lineage

18. Primary GI Lymphomas
• Extra-nodal Marginal zone lymphoma
• DLBCL
• Enteropathy associated T cell lymphoma
• Follicular lymphoma
• Burkitt lymphoma
• Mantle cell lymphoma

19. Diagnostic criteria
Dawson’s criteria are used for labeling primary gastrointestinal
lymphoma:
(1) absence of peripheral lymphadenopathy at the time of
presentation
(2) lack of enlarged mediastinal lymph nodes
(3) normal total and differential white blood cell count
(4) predominance of bowel lesion at the time of laparotomy
with only lymph nodes obviously affected in the immediate
vicinity
(5) no lymphomatous involvement of liver and spleen

20. Staging
Modified Ann Arbor staging Paris Staging Spread of Lymphoma
I1E T1 Mucosa, submucosa
I2E T2 Muscularis propria and subserosa
I2E T3 Serosa penetration
I2E T4 Infiltration of neighbouring organs
II1E T1e4N1 Regional lymph nodes
II2E T1e4N2 Intra-abdominal distant lymph
nodes
IIIE T1e4N3 Extra-abdominal lymph nodes
IV T1e4N0e3M1 Diffuse or disseminated infiltration
of distant or extra-gastrointestinal
organs
B1 Bone Marrow

21. Gastric MALT Lymphoma
 Epidemiology:
• 50 to 60 years
• Female>male
• 50% of the total primary gastric lymphoma
Etiology:
• H. pylori

22. Clinical features:
 upper abdominal symptoms: dyspepsia, nausea, vomiting
 lower abdominal symptoms: disordered bowel habit, vague
discomfort, rectal bleeding
Endoscopic findings:
 minimal changes
 erythema
 thickened folds or erosion

23. Pathogenesis
Evolution of gastric MALT lymphoma is a multistage process
1. Infection of H. pylori
2. Resulting in the recruitment of B and T cells and other inflammatory
cells to the gastric mucosa.
3. The infiltrated B cells are stimulated by the H. pylori-specific T cells
4. Undergo malignant transformation due to the acquisition of genetic
abnormalities.

24. Xavier Sagaert, Eric Van Cutsem, Gert De Hertogh, Karel Geboes & Thomas Tousseyn.
Gastric MALT lymphoma: a model of chronic inflammation-induced tumor development. Nature
Reviews Gastroenterology and Hepatology 7, 336-346 (June 2010).

25. Genetics
 t(11;18)(q21;q21): API2 gene to carboxy terminus of MALT1
 t(1;14)(p22;q32): BCL 10-IGH
 t(3;14)(p14.1;q32):IGH-FOXP1
 t(14;18)(q32;q21): IGH-MALT1
 Causing transcriptional dysregulation of BCL10, MALT1, FOXP1
 Immunoglobulin heavy chain and light chain genes show clonal
rearrangement and somatic hyper mutation
 Activation of NF-ƙB signalling pathway
 Trisomy 3, 12, 18 (often associated with t(1;14)
 p53 mutation; methylation of p15 and p16 promoters
 Mutations of fas

27. DIAGNOSIS

28. Histomorphology
• Dense lymphoid infiltrate
• Prominent lymphoepithelial lesion:
3 or more marginal zone cells with
distortion or destruction of
epithelium, with eosinophilic
destruction of epithelial cells.
• Dutcher bodies in plasma cells
• Infiltration of muscularis mucosae
• Moderate cytologic atypia of
lymphoid cells

29. H&E 100X H&E 400X

30. Wotherspoon scoring system for gastric
lymphoid infiltrates
Score Diagnosis Histologic features
0 Normal Scattered plasma cells in lamina
propria. No lymphoid follicles
1 Chronic active gastritis Small clusters of lymphocytes in
lamina propria. No lymphoid follicle
no lymphoepithelial lesions
2 Chronic active gastritis with florid
lymphoid follicle formation
Prominent lymphoid follicles with a
surrounding mantle zone and
plasma cells. No lymphoepithelial
lesions
3 Suspicious lymphoid infiltrate,
probably reactive
Lymphoid follicles surrounded by
small lymphocytes infiltrating
diffusely in lamina propria,
occasionally into epithelium

31. Score Diagnosis Histologic features
4 Suspicious lymphoid infiltrate,
probably lymphoma
Lymphoid follicles surrounded by
marginal zone cells that infiltrate
diffusely in lamina propria and
occasionally into epithelium
5 MALT lymphoma Presence of dense diffuse infiltrate
of marginal zone cells in lamina
propria with prominent
lymphoepithelial lesions

32. Immunoprofile:
 Express Pan B cell markers CD19, CD20, CD22, CD79a, PAX5
 Express surface immunoglobulin: IgM or IgA
 Aberrant expression of CD43
 MALT1 expression
 Negative for CD5, CD23, CD10, CyclinD1 and Bcl-6
 Light chain restriction(kappa>lambda)
 CD21 and CD23 for follicular dendritic cells
 Nuclear BCL10 in t(11;18)
 Perinuclear BCL10 in t(14;18)

33. CD 20 CD 43
KAPPA LAMBDA CD 5CD 23

34. Detection of Helicobacter pylori
• Stains: Giemsa, Warthin starry, Toluidine blue.
• Urea breath test
• Rapid urease test
• Culture: Brain heart infusion broth
• Stool polymerase chain reaction based studies

35. Molecular pathology in diagnosis
• PCR based analysis of B cell clonality:
• Selective amplification of rearranged IGH genes
• Detection of recurrent genetic abnormalities:
• FISH for t(11;18)(q21;q21)/API2-MALT1,
• t(14;18)(q32;q21)/IGH-MALT1,
• t(1;14)(p22;q32)/IGH-BCL 10
• t(3;14)(p14;q32)/IGH-FOXP1
Normal
Break in MALT1 gene

36. Immunoproliferative small intestine
disease(IPSID)
• Subtype of MALT lymphoma
• Associated with Campylobacter jejuni
• Has characteristic geographic
distribution, clinical presentation and
histologic appearance.
• Young adults of low socioeconomic
background.
• Endoscopic findings: involvement of
duodenum by polypoid or flat lesions
• Histopathologic findings: blunting or
flattening of villi with a predominance
of atypical plasma cells in the lamina
propria

37. Diagnostic Difficulty
• Diffuse large B cell lymphoma:
• Presence of large cells in clusters (>20 large cells)
• WHO recommendation: cases showing transformation should be diagnosed
as DLBCL
• CD 10 and BCL6 positive
• Reactive follicles:
• Centrocyte like cells over-run the lymphoid follicles
• CD21 highlights expanded follicular dendritic cell meshwork
• Follicular lymphoma:
• Neoplastic cells selectively infiltrate, replace and expand germinal centres
• These cells lack germinal centre markers(CD10 negative)

38. • Reactive inflammatory process:
• That typically precede the lymphoma
• Example: H. pylori gastritis, LESA, Hashimoto’s thyroiditis
• Lymphomas: CLL, Mantle cell Lymphoma

39. THERAPY

40. Therapy of MALT Lymphoma
• H. pylori dependence:
• CD86 (B7.2)
• CD4+CD56+ Treg: FOXP3
• Methylation: p16INK4A Methylation-specific PCR
• HP-specific protein: CagA protein
• HP-specific protein: Serum CagA IgG antibody

41. • H. pylori independence:
• Chromosome t(11;18)(p21;q21)
• Chromosome t(1;14)(p22;q32)
• Protein BCL10 nuclear expression
• Chemokine/chemokine receptor CXCR3

42. Therapy of GI MALT lymphoma
• Anti H. pylori eradication therapy
• MALT cells proliferate in presence of H. pylori
• T cell regulated proliferative drive is contact dependent
• Hence detection of H. pylori infection is crucial for treatment of these
lymphomas
• t(11;18) is associated with resistance to anti H. pylori therapy
• When therapy is deemed to have failed or delayed response is seen
standard anti lymphoma therapy is indicated.

43. Therapy of GI MALT lymphoma
• Anti H. pylori therapy: triple therapy of omeprazole(20mg),
clarithromycin(250mg), metronidazole(400mg)
• Radiotherapy
• Chemotherapy: CHOP, Chlorambucil, fludaribine and cladribine
• Monoclonal antibody therapy: Rituximab

44. Prognostic factors
• Staging: stage 2E or above are unlikely to respond to antibiotic
therapy
• Histologic features:
• presence of DLBCL with or without low grade MALT lymphoma component.
• MALT lymphomas containing <1% or >5% diffusely intermingled large blasts,
no overt DLBCL, show worse outcome.
• Molecular genetic changes:
• t(11;18)(q21;q21): associated with failure of antibiotic treatment

45. Post treatment biopsies
• Biopsies are taken every 3-6 months for the first 2 years and yearly
thereafter.
• Continued monoclonality is associated with delay in achieving
remission.
• GELA scoring

46. Assessment of post eradication biopsies: Group
d’Etude des lymphomes de l’Adulte(GELA) scoring
GELA CATEGORY MORPHOLOGICAL FEATURES RECOMMENDATION
CR- complete histological response Empty appearance of lamina
propria with fibrosis, few glands,
small lymphocytes and plasma
cells; no LEL
No need of additional therapy
pMRD- probable minimal residual
disease
Base of lamina propria and/or
submucosa with small lymphoid
nodules and fibrosis; no LEL
No need of additional therapy
rRD- responding minimal residual
disease
Presence of lymphomatous
infiltrate in a diffuse or nodular
pattern; some degree of stromal
change(thin areas of fibrosis); focal
or no LEL
Evaluation of clinical progression
should delineate additional therapy
NC- no change Dense lymphomatous
infiltrate(diffuse or nodular) similar
to diagnostic biopsy; LEL present
Oncologic treatment should be
proposed if infiltrate persists over
sequential examinations

48. Conclusion
• MALT Lymphoma is a specific lymphoma entity with characteristic
clinical, pathologic and molecular features.
• In stomach, associated with H. pylori infection.
• H. pylori detection is crucial for treatment.
• Certain characteristics, including depth of involvement, local lymph
node involvement and presence of t(11;18)(q21;q21), predict lack of
response to eradication therapy.
• GELA scoring system provides direction of travel of potential
lymphoma regression.

49. References
• Molecular Pathogenesis of MALT Lymphoma Katharina Troppan, KerstinWenzl,
Peter Neumeister, and Alexander Deutsch Division of Hematology, Department of
Internal Medicine, Medical University of Graz(MUG), 8036 Graz, Austria
• Chris M Bacon, Ming-Qing Du, Ahmet Dogan. Mucosa-associated lymphoid tissue
(MALT) lymphoma: a practical guide for pathologists. J Clin Pathol 2007;60:361–
372.
• Lymphomas of the gastro-intestinal tract – Pathophysiology, pathology, and
differential diagnosis. Diana M. Cardona, Amanda Layne, Anand S. Lagoo
Department of Pathology, Duke University Medical Center, Durham, NC, USA.
• Prasanna Ghimire, Guang-Yao Wu, Ling Zhu. Primary gastrointestinal lymphoma.
World J Gastroenterol 2011 February 14; 17(6): 697-707.
• Massimo Pignatelli, Patrick Gallagher. Recent Advances in Histopathology-23.
2014 J P Medical Ltd.

50. THANK YOU