“…As far as the pathological diagnosis is concerned, the transition zone between benign and malignant endometriosis is detectable in only 36-42% of cases, and coexistence of a neoplasm and endometriotic tissue is sufficient to demonstrate the endometriotic origin of the lesion (Figure 1) (36,37). Extra-ovarian malignancies can involve the colon and recto-vaginal septum, and more rarely, the small bowel, vulva, vagina, fallopian tube, urinary tract, pleura and pelvic lymph nodes, thus paralleling the distribution of benign extra-ovarian endometriosis (5,25,35,36,(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49). Scar endometriosis, i.e.…”