ABSTRACT
BACKGROUND: Spinal extradural arachnoid cysts are rare expanding lesions in the spinal canal. Enlargement may cause progressive signs and symptoms caused by spinal cord compression. They are associated with trauma, surgery, arachnoiditis, and neural tube defects. Most nontraumatic spinal extradural arachnoid cysts are thought to be congenital. DESIGN: Case report and literature review. FINDINGS: A 9-year-old boy with mild paraparesis was found to have an extradural multiloculated arachnoid cyst with fibrous septa at T4-L3 levels and anterior compression and displacement of the spinal cord. CONCLUSIONS: Definitive treatment of arachnoid cyst entails radical cyst removal and dura cleft repair. Formation of a postoperative cerebrospinal fluid fistula may require external lumbar drainage.
