RESUMO
BACKGROUND: Primary endometrial stromal sarcomas of the ovary are rare gynecologic malignancies. We report a disseminated case of this tumor arising from ovarian endometriosis. CASE: A 45-year-old woman presented with an abdominal pelvic mass and an elevated CA 125. Exploration showed extensive tumor spread from the ovaries to the upper abdomen. Surgery included a total hysterectomy, bilateral salpingo-oophorectomy, splenectomy, partial gastrectomy, partial pancreatectomy, transverse colectomy, appendectomy, and omentectomy. Final pathology showed a low-grade endometrial stromal sarcoma of the ovary arising from foci of endometriosis. Megestrol acetate was initiated, and she is currently without evidence of disease. CONCLUSION: This is an advanced case of a primary low-grade endometrial stromal sarcoma of the ovary arising from endometriosis managed by total resection and progestational therapy.