Benign and malignant neoplasms which occur within the substance of the spinal cord (intramedullary neoplasms) or in the space between the dura and spinal cord (intradural extramedullary neoplasms). The majority of intramedullary spinal tumors are primary CNS neoplasms including astrocytoma; ependymoma; and lipoma. Intramedullary neoplasms are often associated with syringomyelia. The most frequent histologic types of intradural-extramedullary tumors are meningioma and neurofibroma.