Metastasizing uterine tumor resembling ovarian sex cord tumor (UTROSCT)

An enigmatic category of uterine mesenchymal neoplasms is descriptively referred to as uterine tumors resembling sex cord-gonadal stromal tumor. First described by Clement and Scully in 1976, they were subsequently subcategorized in 1) endometrial stromal tumors with sex cord-like elements (ESTSCLE) and 2) mural uterine tumors resembling ovarian sex cord tumors (UTROSCT). In the first subcategory, the prognosis depends on the type, grade, and stage of the underlying stromal neoplasm, while in the second one, a low-grade malignant behavior has been postulated on the basis of occasional local recurrences. Here, the authors report a new case of metastasizing UTROSCT in an 83-year-old Caucasian woman, providing a literature review, and emphasizing its metastatic potential. This tumor entity shows a variable immunohistochemical profile with possible co-expression of sex cord (inhibin, calretinin, WT1, MART1/melanA), epithelial, smooth muscle (actin, caldesmon), and miscellaneous markers, such as estrogen or progesterone receptors. For this aberrant expression of immunohistochemical markers, the final diagnosis of metastatic UTROSCT appears a diagnostic challenge. Finally, the authors detected the cdkn2a (p16INK4a) expression in about half of the neoplastic cells; this finding suggests a possible involvement of the CDKN2A gene in the genesis of an aggressive tumor clone, as observed in other uterine sarcomas.