Appendiceal intussusception due to an appendiceal malignant polyp--an association in a patient with Peutz-Jeghers syndrome: report of a case.

A 40-year-old woman with Peutz-Jeghers syndrome and an appendiceal intussusception is reported. In this patient, the lead point was a large sessile, appendiceal polyp. The invaginated and inverted portion of the appendix resembled the long stalk of a pedunculated polyp on roentgenography and endoscopic examination. Histologically, the appendiceal polyp was a villous adenoma with mild to severe atypia and focal carcinoma in situ. In patients with Peutz-Jeghers syndrome, hamartomatous polyps and colorectal adenomatous polyps with highly malignant potential can coexist and must be managed appropriately. Therefore, when evaluating a polypoid or a pedunculated lesion in the cecal lumen, the possibility of an appendiceal intussusception should also be investigated.