A Case of Mature Cystic Teratoma with Malignant Transformation Diagnosed Using Colonoscopy

Abstract

　　Mature cystic teratoma with malignant transformation is a rare disease with an incidence of about 1% among ovarian tumors. Here, we describe how we were able to diagnose pathological tissue preoperatively using colonoscopy. The patient was a 68-year-old woman (gravida 4). She presented with abdominal pain. Her general condition was poor. On examination, we found perforation of an ovarian tumor into the sigmoid colon. Lower gastrointestinal endoscopy was performed and some tissue was retrieved. Pathological analysis of the tissue revealed a diagnosis of squamous cell carcinoma.