Hemorrhagic lumbar synovial cyst.

Synovial cysts of the lumbar spine are an uncommon cause of back and radicular pain. These cysts most frequently present as back pain, followed by chronic progressive radiculopathy or gradual onset of symptoms secondary to spinal canal compromise. Although less common, they can also present with acute spinal cord or root compression symptoms. We report of a case in which hemorrhaging into a right L2-3 facet synovial cyst caused an acute onset of back pain and radiculopathy, requiring surgical excision.