Endometriosis is a benign gynaecological disorder with malignant biological characteristics and is defined by the presence of endometrial glands and stroma outside the uterine cavity. Ectopic endometrial cells can spread to pelvic organs such as rectum, bladder, and ovaries. The pathophysiology of endometriosis is likely to be multifactorial and to involve an interplay between several factors. (Fauser BC, Diedrich K, Bouchard P, Domínguez F, Matzuk M, 2011)