Intermuscular lipoma of the gluteus muscles compressing the sciatic nerve: an inverted sciatic hernia.

The authors report the case of a 50-year-old woman with a benign intermuscular lipoma of the gluteus compressing the sciatic nerve in its course through the sciatic notch. This benign soft-tissue tumor extended into the pelvis, displacing the rectum laterally. Resection was necessary to alleviate symptoms and prevent irreversible damage of the nerve. Wide exposure of the piriformis muscle and sciatic nerve via a transgluteal approach allowed safe lesion removal, and thus avoiding a laparotomy to resect the intrapelvic extension of the tumor. This report features a curious case of soft-tissue tumor growth across the sciatic foramen forming an inverted sciatic hernia. The authors' proposed approach was simple and safe and avoided a laparotomy.