Giant sacral perineurial cyst. A case report.

A rare case of giant sacral perineurial cyst, causing sciatic pain, explored by myelography and computerized tomography, is reported. The cyst, associated with large erosion of the sacrum, was poorly visualized on the myelography, because of its large size, whereas it was better defined on CT scan. Sacral perineurial cysts are usually small and asymptomatic and rarely cause radicular symptoms. The radiological diagnosis and the treatment of these nerve root cysts are briefly discussed.