Bilateral Ovarian Mass: Low-Grade Endometrial Stromal Sarcoma—a Rare Entity

Abstract

Abstract

Background: An endometrial stromal tumor is a histopathologic entity characterized by a monomorphus population of blunt, spindle-to-oblong–shaped cells with scant cytoplasm in an abundant reticulin framework. This entity was first described in 1908, and was well-characterized by Norris and Taylor in 1966. It is classified as: (1) a benign stromal nodule; (2) a low-grade endometrial stromal sarcoma; or (3) an undifferentiated endometrial sarcoma. Endometrial stromal sarcomas usually arise from the uterine corpus. The most common extrauterine site is the ovary. Case: A 50-year-old female presented clinically with an abdominal lump. Radiologic findings were inconclusive and suggestive of a bilateral ovarian mass. Microscopic examination revealed a circumscribed tumor composed of uniform cells, having scanty cytoplasm, and having uniform nuclei showing nest and sex-cord differentiation that was seen blending with intervening stromal cells. Results: Immunoreactivity of tumor cells for cluster of differentiation (CD10) and stromal cells confirmed the most rare diagnosis of an endometrial sarcoma in the ovary. Patient was well on regular follow up and after surgical correction. Conclusions: Given that endometrial stromal sarcomas frequently express estrogen and progesterone receptors, treatment with hormonal therapies may be efficacious for patients with advanced, residual, and recurrent cases. (J GYNECOL SURG 31:351)