Localization

 nodal marginal zone B-cell lymphoma
 extra-nodal marginal zone B-cell lymphoma (MALT lymphoma)

• digestive marginal zone B-cell lymphoma (digestive MALToma)
• pulmonary marginal zone B-cell lymphoma (pulmonary MALToma)
• salivary marginal zone B-cell lymphoma (salivary MALToma)
• splenic marginal zone B-cell lymphoma
• cutaneous marginal zone B-cell lymphoma

Immunophenotype

 pan-B+
 CD5-/+
 CD10-
 CD23-
 CD11c+/-
 cyIg + (40% of the cells)
 sIgM+ bright
 sIgD-

Putative cell of origin: Marginal zone lymphocytes harbouring hypermutated IgV genes

Cytogenetics

 t(11;18)(q21;q21) (API2/MALT1 fusion gene) (30-50% of the low-grade MALT)
 t(1;14)(p21;q32) in extra-nodal MALT lymphoma
 del(7)(q22-31) in splenic MZBCL (40% of the cases)
 trisomy 3 (#7718871#) and +3q (30-70% of the cases) in nodal, extra-nodal and splenic MZBCL

References

 Isaacson PG, Du MQ. MALT lymphoma: from morphology to molecules. Nat Rev Cancer. 2004 Aug;4(8):644-53. PMID: #15286744#

 Taddesse-Heath L, Pittaluga S, Sorbara L, Bussey M, Raffeld M, Jaffe ES. Marginal zone B-cell lymphoma in children and young adults. Am J Surg Pathol. 2003 Apr;27(4):522-31. PMID: #12657939#