Extensive Overgrowth of Sex Cord-Like Differentiation in Uterine Mullerian Adenosarcoma: A Rare and Challenging Entity.

Sex cord-like differentiation has been well documented in endometrial stromal tumors. On the basis of the extent of sex cord differentiation, uterine stromal tumors with this kind of differentiation have been classified into 2 subgroups of endometrial stromal tumor with sex cord-like elements and uterine tumors resembling ovarian sex cord tumor. When extensive, this differentiation has been accompanied with indolent clinical behavior and rather good prognosis in most cases. Sex cord differentiation has been rarely observed in uterine mullerian adenosarcoma. Only 3 cases of such occurrence have been reported in the English literature. Herein, we report a case of uterine mullerian adenosarcoma extensively overgrown by uterine tumor resembling ovarian sex cord tumor in a young woman. The presence of an ovarian sex cord tumor component has been confirmed by immunohistochemistry. To the best of our knowledge, this is the second report of such a case in the English literature.