2017 Volume 76 Issue 2 Pages 79-82
Mature teratoma of the ovary is the most common ovarian disease. However, due to its rarity, it is difficult to predict the occurrence of malignant transformation in mature teratoma. Current studies have suggested that preoperative factors include ovarian tumor size, tumor marker, and the age of the patient. We studied 471 patients with benign mature teratoma and 8 patients with malignant transformation who underwent surgery at the Department of Obstetrics and Gynecology, Nihon University Itabashi Hospital between 2003 and 2015. Most patients with malignant transformation in mature teratoma exhibited larger ovarian tumors, with high concentrations of squamous-cell-carcinoma antigen, and were older. We propose that the addition of considering the ovarian tumor size, tumor marker level, and patient age, along with imaging findings, will be effective in the preoperative differential diagnosis of mature teratoma and malignant transformation.