Georgetown University School of Medicine 3700 Reservoir Rd Washington DC 20007 USA;
Department of Neurosurgery Medstar Georgetown University Hospital 3800 Reservoir Rd Washington DC 20007 USA;
Department of Neurosurgery University of Pittsburgh Medical Center 200 Lothrop St.Ste B400 Pittsburg PA 15213 USA;
Chordoma; Extraosseous; Nerve root; Cervical spine; Intradural extramedullary;