Intussusception of the appendix.

Two cases of intussusception of the appendix are reported--one caused by adenocarcinoma and adenomatous polyp and the other by an endometrioma. Appendiceal intussusception and adenocarcinoma are both uncommon entities and this is the first report of the two occurring concomitantly. Due to variable symptoms, the correct diagnosis of appendiceal intussusception has rarely been made preoperatively. Classification, symptoms, radiographic appearance, and differential diagnosis are discussed, and the authors suggest a new classification for intussusception of the appendix.