Sclerosing stromal tumor of the ovary: a case report

Sclerozing stromal tumor of the ovary is an extremely rare neoplasm occurring predominantly in the second and third decades of life. Most patients have menstrual irregularities and pelvic pain. Infertility and endometrial pathology have also been described. A 34-year-old woman presented with hirsutism and oligomenorrhea of three months duration. Ultrasound examination showed a heterogeneous right ovarian tumor consisting of predominantly solid tissue with several loculated cysts. On T2-weighted pelvic MR images, signal intensities of the cystic components were high and those of the solid components were heterogeneous, ranging from intermediate-high to high. Dynamic MRI marked early enhancement of solid components in the right ovary. The specimen obtained from endometrial curettage showed proliferative endometrium. Preoperative serum levels of tumor markers were in normal range: preoperative serum levels of testosterone (T) (2.42 ng/ml; normal for adult females 0.1-0.8 ng/ml) and dehydroepiandrosterone-sulphate (DHEA-S) (232.4 microg/dL; normal for adult female, 35-430 microg/dL) were measured and the T value was found increased. At laparotomy, a left ovarian mass was found attached to the right infundibulopelvic ligament and a left oophorectomy was performed. The mass was described as benign by frozen analysis. Definitive histopathological diagnosis was sclerozing stromal tumor of the ovary (SST). The histologic features included a pseudolobular pattern with focal areas of sclerosis and a two-cell population of spindled and polygonal cells. Immunohistochemical studies showed positive smooth muscle actin and negative cytokeratin, keratin, S100 and desmin. The T value decreased postoperatively (0.57 ng/ml).