Diffuse gastrointestinal involvement of mantle cell lymphoma.

: The gastrointestinal tract is the predominant site of appearance of extranodal non-Hodgkin lymphomas. The most frequent endoscopic finding of mantle cell lymphoma is multiple lymphomatous polyposis, which is a very rare entity. Multiple lymphomatous polyposis is characterized by multiple polypoid lesions involving long segments of the gastrointestinal tract and it accounts for 2% of primary gastrointestinal tract lymphomas. A 68-year-old patient was admitted to our clinic with intermittent diarrhea, weight loss, hematochezia and fatigue. Multiple lymphomatous polyposis was detected on the endoscopic evaluations. Gastrointestinal mantle cell lymphoma was confirmed with histopathological and immunohistochemical studies on biopsy specimens from colon, small intestine and stomach. The patient was successfully treated by combination chemotherapy.