POSTERIOR THECAL LUMBAR DISC HERNIATION MIMICKING SYNOVIAL CYST

We describe a 70 year-old-patient with a rare, misleading presentation of lumbar disc prolapse, which on CT mimicked a synovial cyst. The wh ole nucleus pulposus had herniated, become sequestrated, and migrated behind the theca adjacent to the L4-5 facet joint. There was no contin uity of the disc material with the intervertebral space. A fenestratio n was performed and the sequestrated disc material was found free of a dhesions, and removed completely without difficulty. Histopathological examination confirmed the diagnosis. The patient had complete relief from his pain.