Abstract

Development of a malignant tumor within a mature cystic teratoma is a serious event, and occurs in about 1%~4% of cases. The malignant transformation occurs most frequently in the squamous epithelium with the formation of a squamous cell carcinoma. There are 10 cases reported in the literature, in Korea. We report 4 additional cases, which include 3 squamous cell carcinomas and 1 adenosquamous carcinomas, arising in cystic teratoma of the ovary.