Endometriosis within a left-sided inguinal hernia sac

Endometriosis is a common gynecologic disorder wherein ectopic endometrial glands and stroma are found at extrauterine sites. Extrapelvic endometriosis is a well-documented, yet rare, disease entity that can affect almost any organ system. Inguinal endometriosis is an extremely rare disease entity characterized by tender inguinal swelling. Here we report a case of a sudden-onset and acutely painful left inguinal hernia with concordant endometriosis. A review of the literature is presented. The presence of isolated endometriosis contained within a left-sided inguinal hernia sac has, to our knowledge, never been reported. Often diagnosed incidentally or on histologic examination, general surgeons should consider inguinal endometriosis in the differential diagnosis of inguinal masses, even in the absence of catamenial symptoms. Surgical excision, with gynecologic follow-up, is locally curative and the treatment of choice for inguinal endometriosis.