Splenic marginal zone lymphoma--a clinicopathological study in a series of 16 patients.

Splenic marginal zone lymphoma (SMZL), characterized in the WHO classification of lymphoid tumors, is a rare disorder comprising less than 1% of lymphoid neoplasms; only a few series concerning this entity have been published. Although this type of lymphoma is well defined histologically, its histogenesis remains obscure. Moreover, specific biological markers are still lacking and immunophenotype profile is not specific. These and other reasons, such as the existence of cytogenetic subtypes, have led to some authors to suspect that SMZL constitutes a heterogeneous entity. We have analyzed a series of sixteen SMZL cases from four hospitals in our community, from a clinical, biological and pathological point of view. When compared with those reported in the literature, our findings show three main differences: our patients less frequently showed an intrasinusoidal bone marrow infiltration pattern; the presence of a serum monoclonal component was rarely seen; and CD5-positive SMZL cases appear to be more common than previously thought.