Low-Grade Endometrial Stromal Sarcoma Arising From Sciatic Nerve Endometriosis

Abstract

Endometrial stromal sarcoma arising from extrauterine endometriosis is a rare and not easily diagnosed tumor. We present a case arising from sciatic nerve endometriosis in a 50-year-old woman. The patient had a long history of endometriosis and presented with a left buttock mass and motor deficit. Magnetic resonance imaging showed a large tumor of the sciatic nerve with pelvic extension. She underwent total hysterectomy, bilateral salpingo-oophorectomy, and excision of pelvic endometriotic pockets, allowing the diagnosis of low-grade endometrial stromal sarcoma arising from endometriosis. She received systemic chemotherapy, gonadotropin-releasing hormone agonist therapy, and palliative radiation therapy, but her disease progressed. Aggressive endometriosis raises important diagnostic and therapeutic difficulties and may correspond to misdiagnosed rare malignant neoplasms, which should be treated.