Brain and spinal cord tumors are found in the tissue inside the skull or the bony spinal column, which makes up the central nervous system (CNS). A tumor is a mass of cells that forms from an abnormal cell growth or is present at birth (congenital). Tumors occur when genes that regulate cell growth become damaged or mutated, allowing cells to grow and divide out of control. Tumors can form anywhere in the body.
Depending on the type, a growing tumor can kill healthy cells or disrupt their function. It can displace or compress sensitive tissue and block the flow of blood and other fluid, causing pain and inflammation. A tumor can also block the normal flow of electricity in the brain or nerve signaling to and from the brain. Some tumors are benign and rarely cause any problem.
There are more than 120 types of brain and spinal cord tumors. Some are named by the type of cell in which they start (such as glioma) or location (such as meningioma, which form in the lining of the brain and spinal cord). Spinal tumors are classified according to their location in the spine. There are usually classified as vertebral tumors (within the bone), intramedullary tumors (within the spinal cord) or intradural-intramedullary (with the lining around the spinal cord) tumors. Most of the tumors that affect the vertebral body arise from other areas of the body such as the prostate, the breast, the lung or the kidneys.
The demographics vary with the type of tumor. Spinal cord tumors are less common than brain tumors. Although they affect people of all ages, spinal cord tumors are most common in young and middle-aged adults. According to the National Institutes of Health (NIH), nearly 3,200 central nervous system tumors are diagnosed each year in children under age 20.