Carcinoid-related angiomatous polyposis simulating Crohn disease

Polyposis associated with ileal carcinoid tumors is a rarely described path ologic mucosal transformation that may simulate inflammatory or neoplastic polyps. We describe a case with innumerable sessile polyps and groups of la rge filiform-like polyps of the terminal ileum associated with submucosal c arcinoid tumors and a large mesenteric carcinoid tumor mass. The clinical, radiographic, and endoscopic presentation of the polyposis, together with t he presence of multiple small bowel stenotic lesions, simulated Crohn disea se, We propose the descriptive terminology angiomatous polyposis to describ e the striking microscopic vascular proliferation that characterizes these polyps. The distribution of these lesions, with the most profuse polyposis in the immediate proximity of the carcinoid nests, and the immunohistochemi cal demonstration of growth factor substances, such as transforming growth factor a! within neoplastic cells and adjacent polyps, suggest a tumor fact or-mediated stromal proliferation.