Gastrointestinal mantle cell lymphoma with isolated mass and multiple lymphomatous polyposis: report of two cases.

We herein report two patients with mantle cell lymphoma (MCL), who had isolated mass and multiple lymphomatous polyposis (MLP) in the gastrointestinal tract. In case 1, esophagogastroduodenoscopy revealed a protruding mass in the duodenum and double-balloon endoscopy disclosed numerous polypoid lesions in the ileum. Case 2 had polyposis in the duodenum and a large mass-forming lesion in the ascending colon. Based on the histologic and immunohistochemical findings of the biopsy specimens, the diagnosis of MCL was made in both patients. A combination of isolated mass and MLP is considered as characteristic endoscopic findings of intestinal lesions of MCL.