Extranodal Marginal zone – MALT lymphoma
§ Often a history of chronic inflammatory/ AI conditions
Sites of involvement § GI tract 50% - Stomach (H. Pylori) § Lung § Parotid (Sjogren’s syndrome) § Ocular adnexae (C. Psittaci) § Skin (assoc with Borrelia borgdorferi), § Thyroid (Hashimoto’s thyroiditis) § Breast
Clinical Features § Bone marrow involvement in 20% § May get multiple extranodal sites
Morphology § Lymph nodes § Infiltrate around reactive B-cell follicles § May spread out to form larger confluent areas and eventually overrun some of the follicles § Glandular tissue § Epithelium is often invaded § Lymphoepithelial lesions
Immunophenotype § Positive : CD20, CD79a, CD21, CD35 § Negative : CD5, CD10, CD23, Cyclin D1
Genetics § t(11;18) - 20% of cases - only 20% of these patients regress with H. Pylori erradication (c.f. 70+ % when the cytogenetics are normal) § t(1;14) - less common § Both mutations cause activation of the NFkB pathway TreatmentGastric § Helicobacter eradication results in regression in 70% § Radiation sensitive § Single agent chlorambucil or R CVP Non-Gastric § Usually indolent § May respond to surgery, radiotherapy or chemotherapy
Nodal Marginal Zone Lymphoma
Clinical Features § Lymphadenopathy § Careful history to exclude extranodal MALT lymphoma (present in 1/3) § Endoscopy § IgM monoclonal gammopathy may also occur
Morphology § Marginal zone and interfollicular areas infiltrated § 2 types described § One resembles nodal involvement by MALT § One resembles SMZL
Immuno § Similar to MALT § Cytogenetics not the same as MALT
§ Median survival 10 years |
Haemato-oncology > Mature B Cell neoplasms >