The pathologic changes of tumors occurring in the epidural space of the spinal intravertebral canal have received less attention than have the pathologic changes of intradural tumors. We have, therefore, reviewed the spinal extradural compressive lesions encountered in a ten year period (1934-1944) in the material of the Laboratory of Neurosurgical Pathology of the Hospital of the University of Pennsylvania. These formed a series of 54 cases and comprised roughly 30 per cent of the total number of mass lesions of the spinal canal. The material is entirely surgical, all patients having undergone laminectomy for relief of cord compression. Symptoms of cord involvement were in all cases the primary complaint, even though the lesion was subsequently found to extend beyond the intervertebral canal, to originate at a distance or even to be a part of systemic disease. The pathologic material has been carefully reviewed and correlated with the clinical course.