Giant thoracolumbar extradural arachnoid cyst: a case report.

This report is presented to demonstrate the image findings of a patient with a recent onset of progressive spinal cord compression caused by a giant arachnoid cyst of the thoracolumbar spine. The patient presented with gradual onset paraparesis and the diagnosis of arachnoid cyst was made on MRI. Surgery was successful with respect to in-toto removal of the cyst, following which there was reversal of cord compression and symptoms. Histological diagnosis was of an arachnoid cyst.