At colonoscopy there were innumerable polyps (from 0.5 to 3 cm) extending from the rectum (Fig. 1) to the cecum (Fig. 2), in spite of a colonoscopy that identified any lesions two years before. Upper GI endoscopy disclosed multiple small, sessile polyps in the stomach and in the duodenum. Fig. 1 Polyposis of the rectum. Fig. 2 Polyposis of selleck products the cecum. Histopathologic study of endoscopic biopsies from the colon and the stomach showed an uniform lymphoid infiltrate. Immunoistochemical evaluation confirmed that the lymphoma was positive for CD20 and cyclin D1, while it was negative for CD10, CD23 and CD5, features compatible with diagnosis of non-Hodgkin mantle lymphoma. Bone narrow biopsy was negative for lymphoid proliferation. Abdominal and pelvis TC revealed anomalies of the rectum wall, pelvic lymphadenopaty and two liver metastasis.

Abdominal and pelvis RM imaging showed lombo-aortic lymphadenopaty and massive thickening of the rectum. Total body PET-TC detected rachis involvement, specifically at D1, L2 and L3 vertebrae, and an intense signal of the whole ileum. The patient was transferred to Department of Haematology to plan chemotherapeutic strategy. Discussion and conclusion The gut mucosa contains more lymphocytes than the other immune system organs. Nevertheless, only 10% of all lymphomas present in the gut (5). Most of primary GI NHL occur with single lesion, which more frequently involves the stomach and small intestine. Single colorectal lymphomas are relatively rare (6). MCL is an uncommon type of primary GI NHL with particular clinic, morphological and immunophenotypic features.

Clinically, patients with a diagnosis of MCL are often elderly adults with a male predominance and present a disease in an advanced stage (7). Abdominal pain, diarrhea, hematochezia and organomegaly are the most common presenting symptoms (8). Liver and spleen involvement are common clinical features too (9). The incidence of GI tract involvement ranged from 10% to 28% in various series (10). The typical endoscopic findings of early MCL is the appearance of MLP with innumerable, small, spherical or hemispherical polyps (11). On the other hand, when an advanced MLP is identified we can classify endoscopic features in three types: 1) elevation type; 2) diffuse infiltration type and 3) ulceration type (12). The diagnosis is finally based on peculiar immunoistochemical findings.

MCL cells can express B cell markers including CD19, CD20, CD22, as well as T cell marker such as CD5, and cyclin D1. The classic cytogenetic t (11, Batimastat 14) translocation with subsequent overexpression of cyclin D1 protein, caused by the translocation of the cyclin D1 gene to the promoter of the immunoglobulin heavy chain, are diagnostic for MCL (13). In the series of MLP cases by Ruskone-Fourmestraux et al.