Occult intrasacral meningocele: clinical and radiographic diagnosis.

We evaluated four patients who had occult intrasacral meningocele with multimodality radiographic imaging techniques. The clinical features, radiological findings, gross appearances of the lesion at surgery, surgical technique, histopathological features of the cyst wall, and surgical outcome are described. The role of magnetic resonance imaging in the preoperative evaluation compared with standard radiographic techniques is discussed. Theories regarding the pathogenesis of this lesion are reviewed.