A case of ovarian endometrioid adenofibroma of borderline malignancy: Evidence for estrogen-producing tumor

A case of ovarian endometrioid adenofibroma of borderline malignancy with an increased serum estradiol level, which rapidly disappeared after removal of the tumor, is reported. Vaginal cytologic analysis showed estrogenic effects, and endometrial cystic glandular hyperplasia was thought to be the reason for genital bleeding. To determine the origin of estradiol production in the tumor, stromal cells were enzymatically isolated from the tumor and cultured in vitro. Estradiol levels in the cultured media increased in parallel with cell growth. This is the first report showing estrogen secretion from stromal cells in an ovarian endometrioid adenofibroma.