Endometrial hyperplasia is an overgrowth of endometrial glands, with different shapes and sizes, which causes increased endometrial thickness. There is a higher proportion in the gland/stromal ratio than observed in normal endometrium. Under the spectrum of endometrial hyperplasia different pathologies that have the common feature of increasing endometrial thickness. Some of these injuries have virtually no malignant potential while others are clearly premalignant lesions. Tissue evaluation plays a key role in the diagnosis of this entity.
The diagnosis of endometrial hyperplasia should be suspected in women with heavy and frequent menstrual periods or in women with abnormal uterine bleeding, especially if they have risk factors such as anovulation, polycystic ovaries, obesity or taking estrogen therapy. Endometrial hyperplasia produces abnormal uterine bleeding in both premenopausal and postmenopausal patients being the cause of 10% of abnormal uterine bleeding and 15% of postmenopausal vaginal bleeding.