Skip to content
My WebMD Sign In, Sign Up

Brain Cancer Health Center

Font Size

Brain Tumors in Adults

No one knows what causes brain tumors; there are only a few known risk factors that have been established by research. Children who receive radiation to the head have a higher risk of developing a brain tumor as adults, as do people who have certain rare genetic conditions such as neurofibromatosis or Li-Fraumeni syndrome. But those cases represent a fraction of the approximately 35,000 new primary brain tumors diagnosed each year. Age is also a risk factor -- people over the age of 65 are diagnosed with brain cancer at a rate four times higher than younger people.

A primary brain tumor is one that originates in the brain, and not all primary brain tumors are cancerous; benign tumors are not aggressive and normally do not spread to surrounding tissues, although they can be serious and even life threatening.

Recommended Related to Brain Cancer

Jean Smart Takes a Leading Role in Battling Brain Cancer

Jean Smart is used to changing roles. The blond beauty first made audiences laugh as Charlene Stillfield on CBS's Designing Women sitcom, won two Emmy Awards as Lana Gardner on NBC's Frasier, and took home a third for her role on ABC's comedic hit Samantha Who? in 2007. She also made a splash as the emotionally unstable but smart wife of the president in the fifth season of Fox's TV thriller 24 in 2006. Now, in one of her most important roles yet, the Seattle native has joined forces with the Chris...

Read the Jean Smart Takes a Leading Role in Battling Brain Cancer article > >

The National Cancer Institute estimates there will be about 23,000 new cases of brain cancer diagnosed in 2012.

 

What Is a Tumor?

A tumor is a mass of tissue that's formed by an accumulation of abnormal cells. Normally, the cells in your body age, die, and are replaced by new cells. With cancer and other tumors, something disrupts this cycle. Tumor cells grow, even though the body does not need them, and unlike normal old cells, they don't die. As this process goes on, the tumor continues to grow as more and more cells are added to the mass.

Primary brain tumors emerge from the various cells that make up the brain and central nervous system and are named for the kind of cell in which they first form. The most common types of adult brain tumors are gliomas and astrocytic tumors. These tumors form from astrocytes and other types of glial cells, which are cells that help keep nerves healthy.

The second most common type of adult brain tumors are meningeal tumors. These form in the meninges, the thin layer of tissue that covers the brain and spinal cord. 

 

What's the Difference Between Benign and Malignant Brain Tumors?

Benign brain tumors are noncancerous. Malignant primary brain tumors are cancers that originate in the brain, typically grow faster than benign tumors, and aggressively invade surrounding tissue. Although brain cancer rarely spreads to other organs, it will spread to other parts of the brain and central nervous system.

Benign brain tumors usually have clearly defined borders and usually are not deeply rooted in brain tissue. This makes them easier to surgically remove, assuming they are in an area of the brain that can be safely operated on. But even after they've been removed, they can still come back, although benign tumors are less likely to recur than malignant ones.

Although benign tumors in other parts of the body can cause problems, they are not generally considered to be a major health problem or to be life-threatening. But even a benign brain tumor can be a serious health problem. Brain tumors damage the cells around them by causing inflammation and putting increased pressure on the tissue under and around it as well as inside the skull.

WebMD Medical Reference

Today on WebMD

human brain xray
Article
Computed Tomography CT Scan Of The Head
Article
 
Integrative Medicine Cancer Quiz
Article
what is your cancer risk
Health Check
 

Malignant Gliomas
Article
Pets Improve Your Health
SLIDESHOW
 
Headache Emergencies
Video
life after a brain tumor
VIDEO
 

Would you consider trying alternative or complementary therapies?


WebMD Special Sections