Adult cecoanal intussusception caused by cecum cancer: report of a case.

We report a case of cecoanal intussusception caused by cecum cancer in a 29-year-old woman. The patient presented to our hospital with a mass protruding from the anus. We manually pushed the mass back into the rectum and performed a gastrograffin enema, which showed a cup-shaped filling defect in the rectum. The defect was moved back to oral side with the pressure of the enema, revealing a tumor originating in the cecum. Colonoscopy showed a protrusion, 5 x 3 cm in size, in the cecum. Laparotomy confirmed that the tumor originated at the bottom of the appendix in the cecum. We performed partial resection of the cecum containing the tumor and appendix. The pathological finding was submucosal adenocarcinoma in adenoma. Cecoanal intussusception is extremely rare and, to our knowledge, this adult case represents the first report documented in the world scientific literature.