Gastrointestinal and Urinary Tract Endometriosis: A Review on the Commonest Locations of Extrapelvic Endometriosis

Extrapelvic endometriosis is a rare entity that presents serious challenges to researchers and clinicians. Endometriotic lesions have been reported in every part of the female human body and in some instances in males. Organs that are close to the uterus are more often affected than distant locations. Extrapelvic endometriosis affects a slightly older population of women than pelvic endometriosis. This might lead to the assumption that it takes several years for pelvic endometriosis to "metastasize" outside the pelvis. All current theories of the pathophysiology of endometriosis apply to some extent to the different types of extrapelvic endometriosis. The gastrointestinal tract is the most common location of extrapelvic endometriosis with the urinary system being the second one. However, since sigmoid colon, rectum, and bladder are pelvic organs, extragenital pelvic endometriosis may be a more suitable definition for endometriotic implants related to these organs than extrapelvic endometriosis. The sigmoid colon is the most commonly involved, followed by the rectum, ileum, appendix, and caecum. Most lesions are confined in the serosal layer; however, deeper lesion can alter bowel function and cause symptoms. Bladder and ureteral involvement are the most common sites concerning the urinary system. Unfortunately, ureteral endometriosis is often asymptomatic leading to silent obstructive uropathy and renal failure. Surgical excision of the endometriotic tissue is the ideal treatment for all types of extrapelvic endometriosis. Adjunctive treatment might be useful in selected cases.