Adenocarcinoma of the appendiceal stump. We have reported the case of a 58-year-old woman with nonspecific abdominal complaints in whom barium enema and subsequent colonoscopy showed a 3 cm lobulated adenocarcinoma within a villous adenoma arising from the appendiceal stump. Because such appendiceal malignancies have no specific clinical signs, symptoms, or radiologic features, preoperative diagnosis is extremely difficult, and colonoscopy may be required to clarify radiologically demonstrated irregularities. 