The brain and spinal cord make up the central nervous system (CNS). Brain and spinal cord tumors are growths of abnormal cells in tissues of the brain or spinal cord. Tumors that start in the brain are called primary brain tumors. A tumor that starts in another part of the body and spreads to the brain is called a metastatic brain tumor.

Brain and spinal cord tumors may be either benign (not cancer) or malignant (cancer).

Both benign and malignant tumors cause signs and symptoms and need treatment. Benign brain and spinal cord tumors grow and press on nearby areas of the brain but rarely spread into other parts of the brain. Malignant brain and spinal cord tumors are likely to grow quickly and spread into other parts of the brain.

There are many types of brain and spinal cord tumors. They form in different cell types and different areas of the brain and spinal cord. The signs and symptoms of brain and spinal cord tumors depend on where the tumor forms, its size, how fast it is growing, and the age of the patient.

Brain and spinal cord tumors can occur in both adults and children. The types of tumors that form and the way they are treated are different in children and adults. In adults, anaplastic astrocytomas and glioblastomas make up about one-third of brain tumors. In children, astrocytomas are the most common type of brain tumor.

The prognosis (chance of recovery) depends on many factors, including age, tumor size, tumor type, and where the tumor is in the CNS.