Metastatic malignant glioma with resultant extradural compression of a sacral nerve root

A patient with a malignant cerebral mixed oligodendroglioma-astrocytoma presented with a severe, painful S-1 radiculopathy. Neuroradiological examinations revealed an extradural soft-tissue mass compressing the first sacral nerve root. Spinal fluid examination and myelography gave no evidence of intradural disease. Surgery confirmed the presence of metastatic glioma compressing the S-1 nerve root. The tumor was entirely epidural in location. Mechanisms of dissemination are discussed.