Malignant transformation of a well-organized sacrococcygeal fetiform teratoma in a newborn male.

We report herein a case of a male newborn with a sacrococcygeal fetiform teratoma (FT). The baby presented with a large coccygeal teratoma. The preoperative diagnosis of FT was made by plain radiography, ultrasonography and magnetic resonance imaging. The baby was successfully treated by complete excision and pelvic floor reconstruction. Postoperative follow-up was uneventful until the teratoma recurred 11 months later as a malignancy. After undergoing a second operative procedure accompanied by chemotherapy, he has been doing well for 18 months.