The coexistence of stromomyoma and uterine tumor resembling ovarian sex-cord tumors. Report of a case and immunohistochemical study.

The case of a 40-year-old female with a uterine tumor resembling an ovarian sex-cord tumor, located within another neoplastic nodule having the histopathological features of a stromomyoma is reported. Light microscopic examination of the uterine sex-cord-like tumor revealed a highly cellular tumor tissue with no specific differentiation, consisting of solid nests and anastomosing cords and a few pseudo-tubular structures. The vacuolated cytoplasm of the lipid-rich cells proved vimentin-positive, but desmin- and keratin-negative. The coexistence of the two variants of endometrial stromal tumor was interpreted as arising from endometrial stroma or multipotential uterine mesenchyme that showed a diverse differentiation toward ovarian sex-cord stroma and uterine smooth muscle with interspersed stromal cell clusters.