Androgen-producing, atypically proliferating endometrioid tumor arising in endometriosis.

A case of androgen-secreting borderline endometrioid tumor arising in endometriosis of the rectovaginal septum is presented. It occurred 10 years after total abdominal hysterectomy and bilateral salpingo-oophorectomy for extensive endometriosis of the fallopian tubes and ovaries, adenomyosis, and leiomyomas of the uterus. We believe 7 years of unopposed continuous oral estrogen replacement therapy contributed to the malignant transformation of the endometriosis.