What Are Adult Brain and Spinal Cord Tumors?
Brain and spinal cord tumors are masses of abnormal cells in the brain or spinal cord that have grown out of control.

In most other parts of the body, it is very important to distinguish between benign (non-cancerous) tumors and malignant tumors (cancers). Benign tumors do not grow into nearby tissues or spread to distant areas, so benign tumors in other parts of the body are almost never life-threatening. One of the main reasons malignant tumors are so dangerous is because they can spread throughout the body.

Brain tumors rarely spread to other parts of the body, but most of them can spread through the brain tissue. Even so-called benign brain tumors can, as they grow, press on and destroy normal brain tissue, which can lead to serious or sometimes even life-threatening damage . For this reason, doctors usually speak of brain tumors rather than brain cancers. The main concerns with brain and spinal cord tumors are:

How fast they grow
How readily they spread through the rest of the brain or spinal cord
Where they are located
If they can be removed (or destroyed) and not come back
But both benign and malignant brain and spinal cord tumors can be life threatening.

Brain and spinal cord tumors tend to be different in adults and children. They often form in different areas, develop from different cell types, and may have a different outlooks and treatments.

Information on these types of tumors in children is covered in Brain and Spinal Cord Tumors in Children.

The central nervous system
To understand brain and spinal cord tumors, it helps to know about the normal structure and function of the central nervous system (CNS), which is the medical name for the brain and spinal cord.

The brain is the center of thought, feeling, memory, speech, vision, hearing, movement, breathing, and much more. The spinal cord and special nerves in the head called cranial nerves help carry messages between the brain and the rest of the body. These messages tell our muscles how to move, transmit information gathered by our senses, and help coordinate the functions of our internal organs.

The brain is protected by the skull. Likewise, the spinal cord is protected by the bones (vertebrae) of the spinal column.

The brain and spinal cord are surrounded and cushioned by a special liquid, called cerebrospinal fluid (CSF). Cerebrospinal fluid is made by the choroid plexus, which is found in spaces within the brain called ventricles. The ventricles and the spaces around the brain and spinal cord are filled with CSF.

Parts of the brain and spinal cord

illustration showing parts of the brain and spinal cord including cerebrum, lateral ventricle, pineal gland, 3rd ventricle, cerebellum, 4th ventricle, brain stem, spinal cord, hypothalamus and pituitary (there is also a close up cross section showing the skull, meninges, cerebrum)