A case of intestinal intussusception with unique hemorrhagic polyps due to AL amyloidosis and excessive anticoagulation.

Most adult intussusceptions are secondary to various pathological conditions that serve as a lead point. Because of their serious nature, intussusceptions often require emergency surgery. We report a surgical case of amyloidosis associated with intussusception, probably due to polypoid protrusions and bleeding tendencies. An 80-year-old man with abdominal pain was suspected of having jejunal intussusception on computed tomography. He had been prescribed warfarin for atrial fibrillation, and excessive anticoagulation was observed with a prolonged prothrombin time/international normalized ratio of 5.44 at presentation. After the excessive anticoagulation was resolved, emergency surgery was performed. The intussuscepted jejunum was resected, and a 7 cm long dark-red pedunculated polyp was identified as the lead point, which was accompanied by multiple small pedunculated polyps. Histopathological examination showed that these were all hemorrhagic polyps. Amyloid depositions were observed in the muscularis mucosae, submucosa, and the walls of the blood vessels. Immunohistochemical analysis revealed immunoglobulin light chain amyloidosis. This case is informative to discuss the clinical sequelae of gastrointestinal amyloid deposition.