This tumor, benign mostly, is very common,
Brain Tumor, Ependymoma 40 5030 (sq 1193-4 3500 4343-3 6912-7 7598-3 9271) Hz
and in general, in the spinal cord,
Ependymoma 70 180 6750 (sq 4087 1726-9 2012-5 4215 5975 8353-5 9230-7) Hz
and a related condition,
Arnold-Chiari Malformation 60 830 2500 (sq 2000 6500 2074-6 4799-3 5270 7490 9862-2) Hz
Merry Christmas.