Symptomatic spinal extradural arachnoid cyst with cord compression in a family: case report.

A family with familial spinal extradural arachnoid cyst is presented. A 14-year-old boy had an extensive T-8 through L-2 dorsal extradural arachnoid cyst with spinal cord compression and slowly progressive myelopathy. His mother had presented 4 years earlier with acute excruciating back pain due to the combination of a lumbar extradural arachnoid cyst at L2-4 and an extruded disc at L3-4. The literature is reviewed in light of the pathogenesis, imaging, and surgical technique required for treatment.