tumour of cranial and spinal nerves: ['A benign or malignant neoplasm arising from a peripheral nerve or the perineural sheaths.', 'Neoplasms which arise from peripheral nerve tissue. This includes NEUROFIBROMAS; SCHWANNOMAS; GRANULAR CELL TUMORS; and malignant peripheral NERVE SHEATH NEOPLASMS. (From DeVita Jr et al., Cancer: Principles and Practice of Oncology, 5th ed, pp1750-1)']