Malignant transformations in ovarian teratomas: a report of four cases.

Mature cystic teratoma (MCT) is a common ovarian neoplasm in young females. A secondary malignant transformation occurs rarely in cystic teratomas at an older age. These secondary malignant neoplasms most commonly are squamous cell carcinomas (SCCs). Various mechanisms are reported, but the exact aetiology is unknown. We report three cases of SCC arising in cystic teratoma and one case of papillary thyroid neoplasm as secondary transformation. The SCCs were arising from the cyst wall, while the papillary thyroid malignancy arose from the normal-looking thyroid epithelium. Histologically, all SCC cases were poorly differentiated. Poor prognostic features for secondary transformations include size more than 10 cm, older age and rapid growth. Data is scarce regarding their appropriate treatment. However, surgical debulking is necessary. Platinum-based adjuvant regimens and taxanes are recommended in cases of advanced disease. In this paper we review and share our experience with this rare disorder.