Multiple malignancies (squamous cell carcinoma and sarcoma) arising in a dermoid cyst of the ovary.

A case of multiple malignancies (squamous cell carcinoma and sarcoma) arising in an ovarian dermoid cyst of a 75-year-old woman is reported: this appears, to the best of our knowledge, to be the first well documented example of such a complex tumor. The two malignant components had a well-demarcated boundary except for at their junction, a feature more indicative of a collision tumor rather than carcinosarcoma of the ovary. The solid sarcomatous portion displayed a prominently myxoid and pleomorphic appearance with a focal whorling and storiform pattern, the features considered to be compatible with the myxoid varient of malignant fibrous histiocytoma recently defined by Weiss and Enzinger. The patient is alive and well 21 months after surgery.