Ileoileal Intussusception Caused by Ileal Neuroendocrine Carcinoma

A 62-year-old man presented with intermittent hematochezia and nonradiating right lower-quadrant pain for 2 weeks. He had a history of atrial fibrillation under warfarin prophylaxis and end-stage renal disease on hemodialysis. Esophagogastroduodenoscopy and colonoscopy did not show identifiable bleeding source. Abdominal computed tomography angiography showed the target sign in the ileum (Figure A). Double-balloon enteroscopy was performed via the oral route followed by the anal route, where 1 nonobstructing 2-cm polypoid tumor was found at midileum (Figure B).