Inguinal endometriosis: a case report

A rare instance of endometriosis, coupled with a right inguinal hernia, is described herein. The patient, a 31-year-old nulliparous Japanese female, reported a palpable right inguinal mass (rounded and soy-bean sized) that became painful during menstruation. Blood counts and other laboratory tests were all within normal limits. By magnetic resonance imaging (MRI), a poorly circumscribed mass, 10 mm across, was visible in continuity with the right round ligament. The mass was isointense on T1-weighted images (T1WIs) but slightly hyperintense on T2WIs (compared to adjacent muscles), showing homogeneous enhancement with intravenous Gd-DTPA contrast. Its presence was detected on diffusion-weighted imaging as well. The MRI showed no signs of associated pelvic disease. Specifically, pelvic endometriosis was not evident, although in addition to inguinal hernia, desmoid tumor, and hemangioma, this was a diagnostic consideration. Laparoscopy was eventually conducted, revealing a small inguinal hernia with a distinct mass peripheral to the sac. Several endometriotic lesions were also observed on the capsule of left ovary. Inguinal herniorrhaphy was thereafter performed, during which the mass and hernia sac were excised together. Histologically, the mass was largely fibrous in nature, with a few endometrial-type glands dispersed, confirming a diagnosis of endometriosis. The patient was discharged 2 days postoperatively in excellent condition. On follow-up, the groin pain had completely resolved.