(Kiosk 2) Inguinal Endometriosis: Rare Cause of Groin Pain

Case Diagnosis: Inguinal Endometriosis

Case Description or Program Description: A 39-year-old female with a history of pudendal neuralgia presented to a sports medicine clinic with right anterior groin pain. She described a pulling sensation of her right lower quadrant that is worse with standing and worse during her menstrual cycle, not associated with Valsalva or cough, and alleviated with sitting. Physical exam demonstrated tenderness to palpation of the pubic symphysis joint and pain with resisted abdominal crunch. She was started on meloxicam and initiated physical therapy dedicated to progressive strengthening of her abdominal muscles.

Setting: PM&R Sports Medicine Clinic

Assessment/Results: An MRI of the pelvis assessing for a sports hernia did not reveal any evidence of adductor injury or hernia. MRI of the pelvis was then performed with endometrial mass staging protocol which demonstrated a right inguinal mass consistent with endometriosis.
The patient was referred to OBGYN for further work up and consideration for endometriosis excision.

Discussion (relevance): Inguinal endometriosis is a rare cause of groin pain that mimics other common inguinal conditions. Patients usually present with groin pain that is associated with menstrual cycles and is more common on the right side. Diagnosing inguinal endometriosis can be challenging since imaging studies may demonstrate non-specific findings. CT may not be helpful in confirming the diagnosis and MRI without contrast may not identify the endometrial mass. MRI with contrast using the endometrial mass staging protocol should be ordered when clinical suspicion is high.

Conclusions: Inguinal endometriosis is a rare cause of groin pain that can often be missed. Providers should be aware of which imaging study to order when suspecting this diagnosis as traditional imaging studies may miss important findings.