An increase in the thickness of the cells of the endometrium, usually due to prolonged exposure to unopposed oestrogen, which can be endogenous, as in anovular menstrual cycles; or exogenous, deriving, for example, from hormone replacement therapy or an oestrogen-secreting tumour. It is classified as simple, complex, or atypical. Endometrial hyperplasia most commonly presents with abnormal uterine bleeding and accounts for 15% cases of postmenopausal bleeding. It may also be asymptomatic, and in some cases regresses spontaneously without ever being detected. The presence of atypical cells may lead to endometrial cancer. Treatment can include progestogen therapy or surgery (see endometrial ablation); hysterectomy is advised when atypical changes are present.
Subjects: Medicine and Health.