Non-MALT marginal zone B-cell lymphomas: a description of clinical presentation and outcome in 124 patients

Marginal zone B-cell lymphoma (MZL) is a recently individualized lymphoma that encompasses mucosa-associated lymphoid tissue (MALT) lymphoma, splenic lymphoma with or without villous lymphocytes, and nodal lymphoma with or without monocytoid B-cells. If the clinical description and outcome of MALT lymphoma is well known, this is not the case for the other subtypes. We reviewed 124 patients presenting non-MALT MZL treated in our department to describe the morphologic and clinical presentation and the outcome of these lymphomas. Four clinical subtypes were observed: splenic, 59 patients; nodal, 37 patients; disseminated (splenic and nodal), 20 patients; and leukemic (not splenic nor nodal), 8 patients. These lymphomas were usually CD5-, CD10-, CD23-, and CD43-, but the detection of one or, rarely, two of these antigens may be observed. Bone marrow and blood infiltrations were frequent, except in the nodal subtype, but these locations were not associated with a poorer outcome. Splenic and leukemic subtypes were associated with a median time to progression (TTP) longer than 5 years, even in the absence of treatment or of complete response to therapy. Nodal and disseminated subtypes were associated with a median TTP of 1 year. However, in all these subtypes, survival was good with a median survival of 9 years, allowing these lymphomas to be classified as indolent. Because of the retrospective nature of this analysis, no conclusion may be drawn on the therapeutic aspects, but conservative treatments seem recommended for leukemic and splenic subtypes.