Spinal Extradural Arachnoid Cyst: Case Report

ABSTRACT

We report a case of thoracolumbar extradural arachnoid cyst in a 39-year-old male who presented with left lower thoracolumbar back pain, left buttock pain, hypesthesia in the left leg for three months. Magnetic resonance image revealed a cystic mass which lies posterior to the spinal cord from T12 to L2 vertebra level. The spinal cord was displaced anteriorly and flattened. We performed total laminectomy from lower half of T12 to upper half of L2 to remove cystic mass which was found to be an extradural lesion. There was a dural opening near the left L1 nerve root sleeve through which cerebrospinal fluid(CSF) was leaking and part of nerve roots were moving back and forth by CSF pulsation. A prompt improvement of the symptoms was noted after surgery. Possible mechanisms of spinal extradural arachnoid cyst and surgical intervention are discussed.