Primary extrauterine endometrial stromal sarcoma: response to hormone therapy

Endometrial stromal sarcomas (ESS) of the uterus are hormone-sensitive tumors. There have been reports in the literature confirming the regression of ESS with progestins, gonadotropin analogues, and aromatase inhibitors. We report a case of primary extrauterine ESS of the rectovaginal septum (RVS), which was poorly responsive and, in fact, progressed on progestin therapy. The question arises: is the evident lack of response to oral progestin in our case an exception or a trend more commonly seen in primary extrauterine, extraovarian ESS? To the best of our knowledge, there has been no report in the literature to address this question. Therefore, we conducted a review of the literature to evaluate the response of these tumors to hormone therapy in relation to their estrogen and progesterone receptor status.