Hemangioblastomas and other uncommon intramedullary tumors.

Astrocytoma and ependymoma make up 90% of intramedullary tumors between them. However, a host of less common tumors form the remaining 10%: these include hemangioblastomas, subependymomas, gangliogliomas and other neuronal variants, metastases from extraneural cancers, and a host of other lesions that typically occur intracranially but which present on rare occasions in the intramedullary location. Most neurosurgeons will encounter the unusual tumors of the spinal cord described in this review only a few times during their professional careers, but it is nevertheless important to recognize the distinct radiological and intraoperative features of those for which significant series of patients have been accumulated. Metastases and germinomas aside, the other neoplasms described here are relatively benign in their clinical and histological behavior, and can be meaningfully resected by careful microsurgical technique.