Uterine carcinosarcomas (malignant mixed Mullerian tumors) are metaplastic carcinomas

Uterine carcinosarcomas (malignant mixed Mullerian tumors) have been traditionally regarded as a subtype of uterine sarcoma. Adjuvant oncological treatments have often been similar to those directed against high-grade uterine sarcomas such as leiomyosarcoma and undifferentiated uterine sarcoma. However, there is now convincing evidence that most uterine carcinosarcomas are monoclonal neoplasms and are in reality metaplastic carcinomas. Although aggressive, the behavior of uterine carcinosarcoma is more akin to that of high-grade endometrioid type endometrial adenocarcinoma and aggressive morphological subtypes of uterine carcinoma. The sarcomatous component is derived from the carcinomatous element which is the driving force. Although the designation carcinosarcoma is likely to remain, adjuvant treatments should probably be similar to those directed against aggressive high grade endometrial carcinomas. Prospective studies should be performed to ascertain whether such adjuvant therapies are more effective than traditional sarcoma based therapies in the treatment of these aggressive neoplasms.