Nerve root compression by a ganglion cyst of the lumbar anulus fibrosus. A case report.

Abstract

A case report of a ganglion cyst rising from the anulus pulposus, causing lumbar nerve root compression. A rare pathologic condition causing sciatica is described. The pathologic anatomy and the magnetic resonance image of the lesion is discussed. A 35-year-old man was subjected to an abrupt twisting motion of the torso during a motor vehicle accident. The patient had a L5-S1 discectomy 1 year before the accident. His low back discomfort and right lower extremity pain were clearly exacerbated by the recent trauma. Magnetic resonance imaging revealed enhancing lobulated epidural mass displacing the S1 nerve. Intraoperative findings were a lobulated cystic mass rising from the degenerated anulus fibrosus, determined on histologic examination to be a ganglion cyst. The patient noted significant relief of the right sciatica after surgery. The appearance and the signal intensity of the epidural mass appear to be important parameters in diagnosing the presence of a ganglion cyst of the anulus fibrous. Excision of the ganglion cyst is indicated in a patient who fails to respond to conservative treatment and where the symptoms correlate with the abnormality seen with magnetic resonance imaging.