A 41-year-old premenopausal woman presented to our hospital with lower abdominal distention and epigastralgia. An ovarian endometriotic cyst was noted when she was 30 years, and was only followed up until she was 36 years. Suspecting rupture of an ovarian tumor, left adnexectomy was performed. The left ovarian tumor was diagnosed as an ovarian carcinosarcoma of the heterologous type occurring in the endometriotic cyst. The carcinosarcoma was composed of an admixture of high-grade carcinomatous and sarcomatous components, including rhabdomyosarcoma. Thereafter, secondary surgery was concluded, which confirmed the tumor stage to be pT1c3. She postoperatively received 6 cycles of docetaxel/carboplatin as adjuvant chemotherapy and achieved recurrence-free survival for 40 months. Among ovarian carcinosarcomas, cases occurring in endometriotic cysts are particularly rare and may have a relatively good prognosis, because tumor cells, especially sarcoma components, tend to be confined to the ovaries. Pathological estimation of the origin of carcinosarcoma is important, because it appears to correlate with prognosis.
Keywords: Carcinosarcoma; Endometriotic cyst; High-grade carcinoma; Ovary; Rhabdomyosarcoma.
© The Author(s) under exclusive licence to The Japan Society of Clinical Oncology 2024. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.