Multiple lymphomatous polyposis associated with small lymphocytic lymphoma: a unique presentation.

Multiple lymphomatous polyposis (MLP) is a rare extra-nodal manifestation of lymphoma. In most cases, MLP is associated with mantle cell lymphoma (MCL). We report a 66-year-old male diagnosed with small lymphocytic lymphoma (SLL)/chronic lymphocytic lymphoma (CLL), who showed evidence of rectal bleeding. A CT-scan of the abdomen and pelvis showed an enlarged spleen, multiple paraaortic and mesenteric lymph nodes, and some diverticular pouching along the antimesenteric border of the pelvic colon. A colonoscopy revealed the presence of multiple polypoid lesions, biopsies of which showed diffuse lymphoid infiltrate without any identifiable follicles. Immunohistochemical analysis combined with a Fluorescence In-Situ Hybridization (FISH) study excluded the diagnosis of MCL. A bone marrow aspiration biopsy demonstrated diffuse infiltration of the bone marrow with low grade lymphocytes that expressed CD 20, CD5 and CD23, with negative BCL-1, t (11; 14) and cyclin D1. A diagnosis of B-cell CLL with kappa light chain restriction was made. Multiple lymphomatous polyposis is considered to be a digestive counterpart to MCL and can therefore be considered as a presentation of MCL. In our case, the polypoid lesions failed to show the characteristic features of MCL. The patient's bone marrow revealed a B-cell lymphoma of CLL/SLL phenotype, which to our knowledge has not been linked to MLP in previously reported cases.