Uterine tumor resembling ovarian sex-cord tumor--a case report and review of the literature.

A uterine tumor resembling an ovarian sex-cord tumor (UTROSCT) is a very rare lesion with only 38 cases reported in the literature so far. Here, we show an additional case of a pure UTROSCT with a DNA stemline at 1c in a 49-year-old woman presenting with abnormal vaginal bleeding. Problems in differential diagnosis arise mainly due to the variable histological picture of UTROSCT. Immunohistochemically, these tumors express cytokeratin, epithelial membrane antigen, vimentin, and smooth muscle actin. Moreover, in some cases, CD99 and alpha-inhibin are detectable. Although 36% of UTROSCT have infiltrative margins, almost all of them behave benignly. It is thus questionable whether the same prognostic criteria apply for these tumors as for endometrial stromal sarcomas. However, in the so-called mixed UTROSCT, the endometrial stromal sarcoma component determines the outcome.