Uterine tumor resembling ovarian sex cord tumor (UTROSCT) is a rare tumor of reproductive-age and postmenopausal women. We present the first case of UTROSCT with cytogenetic analysis. The tumor occurred in a 34-year-old woman who presented with menorrhagia and a uterine mass. Histologic examination showed tumor with features of sex cord-like epithelium and abundant fibromuscular stroma without an endometrial stromal sarcoma component. The tumor cells expressed cytokeratin, CD99, vimentin, desmin, smooth muscle actin, and estrogen and progesterone receptors. The majority of the cells analyzed by cytogenetic studies showed two balanced chromosomal translocations: t(X;6)(p22.3;q23.1) and t(4;18)(q21.1;q21.3). Several known tumor-related genes (bcl-2, MALT-1, FVT1, SCCA1, SCCA2, and DCC at 18q21; RAP1 at 4q21; and STL at 6q23) and a gonadal-development related gene (H-Y regulator gene at Xp22.3) are located at or near the translocation breakpoints. The tumor cells of sex cord–like elements were strongly and diffusely immunoreactive for bcl-2 antibody. These cytogenetic and immunohistochemical data may suggest potential molecular mechanisms of tumorigenesis of UTROSCT.
Uterine tumor resembling ovarian sex cord tumor (UTROSCT) is a rare tumor of reproductive and postmenopausal women that usually presents with abnormal vaginal bleeding or a pelvic mass. Uterine tumors with ovarian sex cord-like differentiation were described in early reports, 1,2 and these tumors were named as uterine tumors resembling UTROSCTs by Clement and Scully in 1975. 3 In their study of 14 cases, they classified UTROSCTs into 2 groups: tumors composed predominantly of endometrial stromal tumor with focal areas of ovarian sex cord-like differentiation (group 1) or tumors consisting predominantly or exclusively of ovarian sex cord-like elements (group 2). Clement and Young also observed that the group 1 tumors followed a clinical course similar to low-grade endometrial stromal sarcoma, while group 2 tumors appeared benign without recurrence after surgery. The histologic features of ovarian sex cord-like differentiation were described as cords, trabeculae, nests, and tubules of epithelial-like cells and occasional eosinophilic bodies resembling Call-Exner bodies. Immunohistochemically, these tumors were shown to consistently express pancytokeratin, vimentin, and smooth muscle actin. Recent studies have shown that these tumors also express α-inhibin and CD99 (MIC2, O13), 3–8 markers usually expressed in normal ovarian sex cord elements and related tumors. 9–13
We report the pathologic, immunohistochemical, and cytogenetic features of a case of UTROSCT. To our knowledge, this is the first case with cytogenetic data that suggests potential molecular defects of these tumors.