Bilateral Endometrial Stromal Sarcoma Originating from Ovarian Endometriosis: A Case Report

Endometrial stromal sarcomas usually develop in the uterine corpus and occasionally arise in various extrauterine sites. Endometriosis is one of the most common benign gynecologic conditions. Malignant transformation is a rare but well-documented complication of endometriosis, occurring in 0.7% to 1% of cases. It can be the cause of some rare malignant tumors like endometrial stromal sarcoma, which is extremely rare at various extrauterine sites. Herein, we describe a surgicaly-proven case of bilateral endometrial stromal sarcoma originating from ovarian endometriosis in a 57-year-old woman.