Solid mature ovarian teratoma with intrarectal protusion: case report.

Background: Primary rectal teratoma is a very rare entity. It has been suggested that these tumors grow from aberrant germinal cells of the embryonic digestive tract. Ovarian tumor can also erode the rectal wall, allowing the formation of a fistula localized inside the rectum, becoming an extremely rare complication.

Clinical Case: We report the first case of a 54-year old woman with transanal bleeding whose endoscopic investigation showed a hairy-covered tumor in its surface localized 15 cm from the anal margin. Scanning detected its exact location and the presence of bony tissue within. By means of a laparotomy, we identified the left ovary fusioned to the anterior face of the rectum where a 5 x 4 cm tumor was originally protruding towards its lumen. Left oophorectomy was performed and through a peri-tumoral section of the intestinal wall we extracted the tumor from the inner rectum and closed the defect with simple sutures. Histological report demonstrated a conglomerate of tissues that corresponded to the three germinal layers.

Conclusions: Although rare, diagnosis of intrarectal ovarian teratoma must be considered as a differential diagnosis in patients with rectal tumors. Diagnosis is relatively easy in the presence of a tumor with a hairy surface that is evaluated endoscopically. For treatment we suggest a simple procedure with adequate results.