Hemorrhage into a lumbar synovial cyst causing an acute cauda equina syndrome. Case report.

Juxtafacet cysts of the lumbar spine have been reported with increasing frequency but their pathogenesis remains obscure. These cysts most frequently present with back pain, followed by chronic progressive radiculopathy or gradual onset of symptoms of spinal canal compromise. The authors report an unusual case of hemorrhage into a right L3-4 synovial cyst causing an acute cauda equina syndrome and describe its successful surgical treatment. The clinical, radiographic, and pathological features are discussed.