Intramedullary tumors

Abstract

Intramedullary tumors may arise in the spinal cord from the intrinsic cell types therein (intra-axial lesions) or get into the spinal cord as metastases from systemic cancer (extra-axial lesion). Intra-axial intramedullary tumors are gliomas and are classified like the intrinsic brain tumors according to the World Health Organization (WHO) grading system [26]. Corresponding to the intracranial compartment, ependymomas, astrocytomas, oligoden-drogliomas, and glioneuronal tumors are found also in the intramedullary segment of the central nervous system. Hemangioblastomas are frequently also found in the spinal cord and are truly intramedullary, but as they arise from the surface are almost an invagination into the cord, displacing and compressing the fiber tracts rather than dissecting them. Tumors are called purely intramedullary from the level of C1 downwards to the end of the cord at the level of the conus. Interestingly, when extending from the cervical cord into the medulla oblongata, a tumor is called cervico-medullary, cervico in this case referring to the intramedullary part in the spinal cord. Tumors of the filum terminale without extension into the conus will in this context not be considered intramedullary. Depending on their location, tumors are cervical, cervi-cothoracic, thoracic, thoracolumbar, and conal. Upward extensions into the medulla oblongata will be called cer-vicomedullary, and further extension into the pons will lead to a tumor being classified as pontomedullary. © 2010 Springer-Verlag Berlin Heidelberg.