Carcinosarcoma in Ovarian Mature Teratoma: A Rare Autopsy Case.

Malignant transformation of an ovarian mature teratoma is a rare phenomenon. The most common malignant tumor is squamous cell carcinoma, followed by other histologic subtypes. Carcinosarcoma in ovarian mature teratoma is much less common, with only several case reports in the literature, and their autopsies have been rarely reported. Here we report a rare autopsy-documented case of ovarian mature teratoma, which has both squamous cell carcinoma and sarcomatous components. The right adnexectomy specimen of a 45-year-old female patient contained non-invasive (in situ) and invasive squamous cell carcinoma and spindle cell sarcoma, which were juxtaposed with transitions between the two, epithelial (carcinomatous) and mesenchymal (sarcomatous), components. The patient died seven weeks after surgery, and an autopsy was performed, revealing significant peritoneal dissemination. For the intraperitoneal dissemination, all were histologically spindle cell sarcoma components, and no squamous cell carcinoma components were identified, suggesting that sarcomatous overgrowth occurred. Sarcomatous components also metastasized to the lung. Death was attributed to peritoneal dissemination of the sarcomatous component. In this case, extensive tissue sampling was performed both in the adnexectomy specimen and the autopsy specimen to conclude that sarcomatous overgrowth in carcinosarcoma is the cause of death.