Extrauterine Low-Grade Endometrial Stromal Sarcoma

Abstract

Summary Objective Endometrial stromal sarcoma is a rare cancer that accounts for 0.2% or less of all female genital tract malignancies. We present a case of extrauterine low-grade endometrial stromal sarcoma arising from endometriosis, which was managed by unilateral salpingo-oophorectomy with postoperative high-dose progesterone adjuvant therapy. Case Report A 28-year-old nulligravid woman had suffered from progressive abdominal distension accompanied by a palpable firm mass for about 3 months. An abdominal pelvic mass, measuring 13 × 12 × 8 cm, was seen on pelvic sonography and abdominal computed tomography. The CA125 titer was also elevated. Left salpingo-oophorectomy was performed when frozen section examination of the tumor indicated a benign tumor. However, the pathology of the tumor was extrauterine low-grade endometrial stromal sarcoma with extensive endometrioid glandular differentiation arising from endometriosis. The resection margin was also involved. The patient has been receiving high-dose progesterone therapy for 2 months without any adverse effects, except for an increase in body weight of 2 kg. Conclusions Low-grade endometrial stromal sarcoma typically has an indolent clinical course and favorable prognosis. Surgical resection is the primary therapeutic approach, and adjuvant therapy with radiotherapy, chemotherapy, or progesterone therapy should be considered for the management of residual or recurrent low-grade endometrial stromal sarcomas.