Ovarian yolk sac tumor with endometrioid carcinoma arising from endometriosis in a postmenopausal woman, with special reference to expression of alpha-fetoprotein, sex steroid receptors, and p53.

A case of a yolk sac tumor (YST) with an ovarian endometrioid adenocarcinoma arising from endometriosis in a postmenopausal woman is described. Clinically, the case showed an aggressive course and did not respond to chemotherapy; the patient died of her disease 6 months after the operation. Histologically, the tumor consisted predominantly of an endometrioid adenocarcinoma, but it also showed microscopic features characteristic of YST. The tumor also contained benign endometriotic lesions with direct transition to the endometrioid adenocarcinoma. Immunohistochemical study revealed that not only the YST, but also the endometrioid adenocarcinoma was partly positive for alpha-fetoprotein. There was an inverse relationship between the endometriosis and the endometrioid adenocarcinoma in terms of the expression of sex steroid receptors and p53: adenocarcinoma cells were positive for p53 but negative for sex steroid receptors, whereas endometriotic epithelial cells were positive for sex steroid receptors but negative for p53.