Endometrial hyperplasia

A condition where the endometrium (lining of the uterus) becomes overgrown, usually related to too much estrogen, or an imbalance between estrogen and progesterone. The most common symptom is abnormal bleeding. Most of the time, it is not considered to be precancerous, unless it contains atypical cells (atypia). Most types of hyperplasia respond well to hormone therapy.