Tumors of the central nervous system having their origin from ependymal cells have long been looked on as a rarity. The reports of workers in the various clinics, particularly of those interested in tumors of the brain, reveal but a relatively small number of ependymal gliomas found in the encephalon. In 1926 Bailey and Cushing1 reported 7 ependymomas among 254 classified gliomas. In a later study Bailey2 found 16 ependymal tumors during an analysis of 566 gliomas. Fincher and Coon3 in 1929 reviewed 8 cases found among 140 cases of glioma at the Sachs clinic. The ependymomas, therefore, would seem to comprise but a small percentage of the glioma family as found in the brain.
The careful investigations of Kernohan, Woltman and Adson4 have revealed a different situation with regard to the number of ependymal tumors found as intramedullary tumors of the spinal cord. In an
ADELSTEIN LJ, PATTERSON GH. SURGICAL TREATMENT OF EPENDYMAL GLIOMA OF THE SPINAL CORD. Arch Surg. 1935;30(6):997-1014. doi:10.1001/archsurg.1935.01180120091008