Intussusception of the appendix vermiformis is an uncommon cause of abdominal pain. Several imaging modalities are of limited value in diagnosing this rare condition, including barium enema, transabdominal sonography, and CT. We report a case of intussusception of the appendix vermiformis with the clinical presentation of intermittent abdominal pain in the right lower quadrant. Colonoscopy revealed an erythematous polypoid lesion at the cecal base. Endoscopic sonography demonstrated a multiconcentric structure and enabled the tentative diagnosis of intussusception of the appendix vermiformis. Laparoscopic surgery with a reduction of the appendix and appendectomy was performed and confirmed the diagnosis. (C) 2006 Wiley Periodicals, Inc. ; 附設醫院內科部 ; 醫學院附設醫院 ; 期刊論文