Endometriosis of the inguinal canal mimicking a hernia.

We report a 37-year-old Chinese woman who presented with a groin lump associated with constant and non-catamenial pain. Ultrasonography was suggestive of an inguinal hernia. Intraoperatively, an endometriotic lump with no laparoscopical evidence of endometriosis in the abdominopelvic region was found. Isolated endometriotic lesions in the inguinal canal is a rare occurrence. Surgeons, however, should consider this diagnosis in women of reproductive age who present with a painful groin lump.