Gastric glomus tumors are rare neoplasms that may present with upper gastrointestinal symptoms, or may be discovered incidentally. They may mimic other tumors both grossly and microscopically. They are usually benign and, although the exceptional case with aggressive behavior cannot be reliably predicted, large size may be of prognostic importance. We describe a 3.8 cm gastric glomus tumor in a patient who also had adenocarcinoma arising in an adenoma of the rectum, and discuss the differential diagnosis and prognosis.