Small-intestinal malignancies are rare. Major risk factors for the development of these malignancies include celiac disease, which predisposes to both carcinoma and lymphoma. Crohn's disease patients have an increased risk of the development of adenocarcinoma, as do the inherited polyposis syndromes, FAP, and Peutz-Jehgers syndrome. Each of these conditions provides unique models for the development of malignancy.