Endometrial Changes Associated with Mifepristone: A Review.

Mifepristone is a well-established pharmaceutical agent in obstetrics and gynecology, which has expanded its therapeutic applications to Cushing's syndrome, meningioma, and even mental disease. The incidence of progesterone receptor modulator-associated endometrial changes (PAECs), characterized by cystic glandular dilatation and architectural complexity that mimic endometrial hyperplasia or carcinoma, is increasing. The precise molecular mechanisms remain incompletely understood. Hormonal influences may be central to PAECs pathogenesis. Histological heterogeneity has been observed between ectopic versus eutopic endometrium. The use of mifepristone at low doses (≤10 mg/d) in young women during the early follicular phase appears to be safe. Monitoring of estradiol(E2) levels before the management is recommended. Risk assessment and preventive strategies, such as intermittent treatment, transvaginal ultrasound and levonorgestrel intrauterine system (LNG-IUS), should be considered.