Spinal tumors can occur inside the cord (intramedullary), within the meninges (membranes) covering the spinal cord (extramedullary - intradural), between the meninges and the bones of the spine (extradural), or they may extend from other locations. Most spinal tumors are extradural. They may be primary tumors originating in the spine, or secondary tumors that are the result of the spread of cancer (metastasis) from other locations -- primarily the lung, breast, prostate, kidney, or thyroid gland.
Any type of tumor may occur in the spine, including lymphoma, leukemic tumors, myeloma, and others. A small percentage of spinal tumors occur within the nerves of the spinal cord itself, most often consisting of ependymomas and other gliomas. The cause of primary spinal tumors is unknown. Some primary spinal tumors are associated with genetic defects. A spinal tumor is much less common than a primary brain tumor.
As it grows, the tumor affects the spinal cord cells, nerve roots, meninges, blood vessels, or the bones of the spine. It causes symptoms because of compression of the spinal cord or nerve roots (similar to spinal cord trauma), invasion of normal cells by the tumor, or ischemia (lack of oxygen) that results from blockage of blood vessels.
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