Spinal extradural arachnoid cyst: review of surgical techniques.

Extradural arachnoid cysts of the spine are a rare cause of spinal cord and nerve root compression, usually in the mid to lower thoracic spine and at the thoraco-lumbar junction in a posterior position. Local pain and myelopathy occur predominantly in young adults, and MRI reveals a well-demarcated extradural lesion, iso-intense to cerebrospinal fluid. We report a 33-year-old woman with an extradural arachnoid cyst from T11 to L1 and review the surgical techniques reported in the literature.