Endometriosis-associated invasive adenocarcinoma involving the rectum in a postmenopausal female: report of a case.

Sampson first reported a case of malignant transformation of endometriosis to adenocarcinoma in 1925. We present a case of such transformation occurring in a postmenopausal female 22 years after total abdominal hysterectomy and bilateral salpingo-oophorectomy. This case demonstrates histologic progression from endometriosis to complex hyperplasia with cytologic atypia, and ultimately to invasive endometrioid adenocarcinoma involving the rectum. Aggressive surgical extirpation of all visible colorectal endometriosis for patients with advanced disease is recommended.