<prompt> Which of the following is not a feature of extramedullary tumour?Early Coicospinal signs and paralysisRoot pain or midline Back -painAbnormal CSFSacral sparing  <response>: Sacral sparing is a feature of intramedullary tumors, not extra medullary tumors. So sacral sparing is the single best answer of choice. Ref: Harrisons Principles of Internal Medicine, 16th Edition, Page 2440 