Definition
Adenomyosis is a benign uterine disease in which endometrial tissues (glands and stroma) are found within the myometrium (wall of the uterus). It has been described as endometriosis interna. In a normal menstrual cycle, the endometrial tissue will grow, becomes thicken, and then shed, resulting in the expected cyclical or monthly menstrual bleeding. If this happens in the uterine wall (myometrium), the resulting bleeding in the wall will cause pain and in the long term, the uterine wall will progressive thicken, thus produces a diffusely enlarged uterus.