Introduction
Brain tumors are composed of cells that exhibit unrestrained growth in the brain.
|
| The major areas of the brain have one or more specific functions. |
They can be benign (noncancerous, meaning that they do not spread elsewhere or invade surrounding tissue) or malignant (cancerous).
Text Continues Below
Malignant brain tumors are further classified as either primary or secondary tumors. Primary tumors start in the brain, whereas secondary tumors spread to the brain from another site such as the breast or lung. (In this report, the term "brain tumor" will refer mainly to primary malignant tumors, unless otherwise specified.)
Benign Tumors
Benign tumors represent half of all primary brain tumors. Their cells look relatively normal, grow slowly, and do not spread (metastasize) to other sites in the body. Benign tumors can still be serious and even life-threatening if they are situated in vital areas in the brain where they exert pressure on sensitive nerve tissue or if they increase pressure within the brain. While some benign brain tumors may pose a health risk, including risk of disability and death, most are usually successfully treated with techniques such as surgery.
|
Click the icon to see an image of a primary brain tumor. |
Secondary (Metastatic) Malignant Brain Tumors
A secondary (metastatic) brain tumor occurs when cancer cells spread to the brain from a primary cancer in another part of the body. Secondary tumors are about three times more common than primary tumors of the brain. Usually, multiple tumors develop. Solitary metastasized brain cancers may occur but are less common. Most often, cancers that spread to the brain to cause secondary brain tumors originate in the lung, breast, kidney, or from melanomas in the skin.
Primary Malignant Brain Tumors
.gif)
