Endometriosis is a pathological entity characterized by the presence of endometrial glands and stroma in ectopic side, out of the uterus and the histological analysis represents the basic examination to a definitive diagnosis. The macroscopic and microscopic features to urological level are similar to those in the others sides and include not only the "usual" aspects of the pathology but also hyperplastic and metaplastic changes both in the glandular and stromal components.