Multiple lymphomatous polyposis of the gastrointestinal tract was initially described as mucosal lymphomatous involvement by any of a variety of Hodgkin's or non-Hodgkin's lymphomas that produced a polypoid appearance over long segments of the gastrointestinal tract. We studied four patients in whom histology revealed diffuse small cleaved cell lymphoma (one case), or intermediate lymphocytic lymphoma of diffuse type (one case), or mantle zone pattern (two cases). All four cases are classifiable as centrocytic lymphoma. Cell suspension and immunocytochemical studies demonstrated B-cells of IgMD or M type with light chain restriction (two kappa, two lambda) showing a B1 + HLA Dr + LN 2+ CD5 + CD10 +. Although all four patients had a partial response to combination chemotherapy, three of them died within 3 years. Analysis of 24 cases reported since 1971 (including the present cases) suggests that MLP is a distinct clinicopathological entity that results from gastrointestinal involvement by a B-cell centrocytic lymphoma. It is distinct from the recently described clinicopathological forms of centrocytic lymphoma and intermediate lymphocytic lymphoma, which both show extensive peripheral lymphadenopathy and splenomegaly, but it is probably closely related to them. The differences are probably attributable to distinct cell tropism or homing properties rather than to cellular histogenesis or degree of maturation.
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