Carcinosarcoma (malignant mixed mesodermal tumor) of the uterus: clinicoimmunohistochemical and histogenetic characteristics.

To search for favourable prognostic factors in carcinosarcoma (CS) on the basis of clinical, morphological and immunocytochemical data, while simultaneously considering the histogenesis of this neoplasm. Thirty two uterine CS patients were analysed based on clinical and morphological data. In addition, each specimen was examined by immunohistochemistry with antibodies characteristic for relevant types of cells and tissues. The presence of both carcinomatous and sarcomatous patterns was observed in all tumours. Among carcinomatous patterns, endometrioid carcinoma was the commonest, while serous, clear cell, and undifferentiated carcinomas were less common. Among sarcomatous patterns, endometrioid sarcomas represented the largest group, while leiomyosarcomas, chondrosarcomas, fibrosarcomas, osteosarcomas, and rhabdosarcomas were rarely observed. Mitotic activity was evidently higher in carcinomas. In seven cases, the expression of both cytokeratin and vimentin was noted in cells of carcinomatous patterns. We found that an early diagnosis (stage I-II) and an initially aggressive surgical cytoreduction were favourable prognostic factors in CS. Furthermore, the presence of cytokeratin-vimentin positive cells in carcinomatous patterns suggests sarcomatous metaplasia of adenocarcinoma. However, the prognostic value of various histological structures of carcinosarcomas could not be identified.