A case of ovarian mature cystic teratoma presenting as a pedunculated ileal tumor.

We report on a 34-year-old Japanese woman who presented with a pedunculated ileal tumor and who was finally diagnosed as having a right ovarian mature cystic teratoma penetrating and protruding into the ileum. She had undergone laparoscopic left ovarian cystectomy, whose specimen was diagnosed as dermoid cyst when she was 27 years old. The colon fiberscope revealed an ileal polyp, diagnosed as mature teratoma. Because of adhesion to the necrotic nodule between the tumor and the right ovary, ileocecal resection and right ovarian cystectomy were performed. The ileal tumor contained tissues of skin, neuroglia, ganglion, choroid, retina, smooth muscle, as well as fibrous and adipose tissues, cartilage, bone, mucous epithelium, and bronchial structures with bronchial glands. The necrotic nodule showed abscess, granulation tissue, foreign body reaction, hairs, normal ileal epithelium, and the ovary with ovums.