EXTRA-PELVIC ENDOMETRIOSIS PRESENTING AS AN INGUINAL MASS

Objectives: The differential diagnosis of groin pain and inguinal masses is broad, but most commonly includes hernias and lymphadenopathy. A much less common etiology of groin discomfort and/or an inguinal mass is extra-pelvic endometriosis. An awareness and understanding of this disease process is important to the general surgeon, who will commonly encounter patients demonstrating inguinal pathology.

Methods: We report a case of a middle-aged woman who presented with chronic inguinal pain associated with a mass, and following surgical exploration was incidentally found to have an inguinal endometriosis of the round ligament.

Results: A 47 year-old female presented with a 14-year history of intermittent right-sided groin pain following the vaginal delivery of her child. She previously underwent numerous gynecologic workups, to include laparoscopy, none of which established a diagnosis. A pelvic ultrasound revealed a 3cm hypoechoic lesion of the right groin. She described a throbbing pain exacerbated with coughing, straining, and prolonged standing. A firm, tender, and mobile mass of the right inguinal region was palpated on exam. A hernia did not seem apparent, and we presumed the mass to represent an inguinal lymph node, which we offered to excise for diagnostic purposes. A standard inguinal incision was made over the mass and dissection carried down to the external oblique fascia. Upon opening the fascia we encountered the round ligament, which contained a small amount of retroperitoneal fat. The ligament was suture ligated and returned to the peritoneum. A 3cm fibrotic mass was identified lateral to the internal ring, and excised using electrocautery. A Bassini hernia repair was then performed, approximating the transversalis fascia and conjoined tendon to the inguinal ligament, followed by closure of the external oblique and skin. Pathology revealed the mass to be endometriosis, of which the patient later reported a family history. Postoperatively she reported improvement in her groin pain and an uneventful recovery from surgery.

Conclusion: Though incredibly uncommon, inguinal endometriosis can cause chronic inguinal pain and present as a tender mass of the inguinal region. The majority of these lesions are diagnosed incidentally following resection, with the surgeon under the presumption that the patient’s symptoms are secondary to a hernia or lymphadenopathy. Despite their rarity, the general surgeon should be aware of this diagnosis, given the volume of patients presenting to general surgeons with inguinal symptomology. Resection appears effective in treating the patient’s symptoms in most cases.