Postmenopausal endometriosis and malignant transformation of endometriosis: a case series

Endometriosis is a common problem in women in their reproductive years but is much less frequent in the postmenopausal state, with an incidence of around 2%. Malignant change in endometriotic deposits was first described by Sampson in 1925. Since then, the risk of malignant transformation has been well documented but continues to be a relatively rare occurrence, occurring mainly (79%) in the ovary. The vast majority of women with this condition are premenopausal or taking exogenous hormones. We undertook a retrospective review of hospital notes identified from our database of endometriosis cases undergoing surgery. We identified two cases of benign disease and two cases of endometriosis-associated adenocarcinoma presenting in menopausal women. The first patient presented with haematuria and rectal bleeding. At laparotomy, she was found to have a substantial endometriotic nodule involving the bladder and sigmoid colon. The second patient presented with abdominal pain and dyschezia. She was found to have uterosacral disease at laparoscopy. The third patient presented with an inoperable endometrioid adenocarcinoma, having previously had a total abdominal hysterectomy and bilateral salpingooophorectomy. The fourth patient presented with pain and an abdominal mass. At laparotomy there was stage IV endometriosis, and histology subsequently revealed an ovarian endometrioid adenocarcinoma. In conclusion, endometriosis can arise de novo in the menopause, perhaps triggered by peripheral conversion of androstenedione or as a consequence of hormone replacement. Persistence of endometriosis past the menopause raises the risk of malignancy. Future research will help to differentiate between those who require radical treatment and those who can be managed conservatively.