Endoscopic appearance of the intussuscepted appendix and accurate preoperative diagnosis.

Intussusception of the appendix in a 25-yr-old man was diagnosed preoperatively. Only six such cases have been reported. This patient presented with episodes of recurrent severe right lower abdominal pain, each episode separated by several uneventful months. The diagnosis was made by radiological visualization of a polypoid lesion with a dimple at the top in the caput cecum, and by the endoscopic appearance of the polypoid mass. A sessile polypoid mass (about 1 cm) that looked like foreskin and glans was observed by colonoscopy. The dimple at the top, like glans, was partially reddish, and the steeply sloped surface, like foreskin turned inside out, was smooth. The area of dimple at the top became discernibly smaller and the appearance changed as air was led into cecum. Appendectomy was without untoward events, and the patient no longer experienced such episodes. Although intussusception of the appendix is rare, it should be included in the differential diagnosis of acute abdominal syndrome.