Understanding Brain Tumors
This information is displayed with permission of the University of Minnesota Cancer Center. For more information about this disease or to review active clinical trials, please visit the website of the Cancer Center.
What is a brain tumor?
A brain tumor is an abnormal growth of cells in the brain. These cells come from the supporting structure of the brain. There are several types of supporting cells. The type and name of your child's tumor is based on the type of supporting cell that begins to grow abnormally.
What is the difference between the brain and the central nervous system (CNS)?
The brain is one part of the central nervous system. The CNS is made up of the brain and the spinal cord.
What do the terms benign and malignant mean? Why are some tumors called benign versus malignant?
This can be confusing. Health professionals often use different words to describe the same disease. Usually a tumor is referred to as malignant when it spreads beyond the original site to other areas or organs. Tumors that begin in the brain usually do not spread to other organs within the body but can sometimes spread in the central nervous system. Even though brain tumors may not spread to other organs, they can cause problems by growing within the head, putting pressure on the normal brain tissue, or destroying healthy tissue.
The dictionary defines benign as mild or harmless and malignant as serious and potentially threatening possibly causing death. This means that some brain tumors, made up of very slow growing cells that do not spread to other locations and can be treated with surgery alone, may be considered benign while other tumors might be malignant even though they remain in the same place.
Are brain tumors cancer?
Again, many different words can be used to describe a brain tumor. A tumor is a mass (lump or cluster) of cells that multiply abnormally for no known reason. Cancer also refers to cells that grow out of control and can spread throughout the body. Some people may not want to call a brain tumor a cancer because it usually does not spread beyond the brain. However, a brain tumor is made of abnormally growing cells that can cause damage. In that sense it is a cancer.
How Common are Brain Tumors?
Brain tumors are the most common occurring solid tumor in children. They are almost as common as childhood leukemia. Approximately 1,700 brain tumors are diagnosed each year in children in the United States. Primary brain tumors account for 20 percent of all childhood cancer deaths. Because they occur so often in children, brain tumors are a major focus of the work of pediatric oncologists, neurosurgeons, and radiation oncologists. Even so, these tumors are rare compared with many other diseases. Doctors from all over the United States have shared their experience and developed national treatment plans for many types of brain tumors.
What Causes a Brain Tumor?
Health professionals honestly do not know what causes a brain tumor. Research has been done for many years to search for causes of brain tumors and is still being conducted today. Past research efforts have investigated areas such as diet, infections, and electromagnetic fields as possible causes; however, none of these factors have been shown to cause brain tumors. We still do not know the cause, but it is likely due to a combination of factors. We do know that brain tumors are not contagious. In some cases, tumors are one part of genetic diseases such as neurofibromatosis and tuberous sclerosis. Children with these diseases have a higher likelihood of developing a brain tumor than other children.
Diagnosis
Brain tumors may have a variety of symptoms, but none of them is specific. These include:
- headache
- visual symptoms, like the crossing of the eyes or sudden development of a "lazy eye"
- gradual loss of movement in an arm or leg
- poor balance
- an eating disorder
- hearing loss
- speech difficulty
If your child experiences these symptoms, which could be caused by a brain tumor, his or her doctor may order a computed tomographic (CT) scan and/or a magnetic resonance imaging (MRI) scan.
Often, surgery is required to determine whether a brain tumor exists and what type of tumor it is. A small sample of tumor tissue may be surgically removed and examined under a microscope. The diagnosis may be made during the surgical procedure by making a fast frozen tissue section which takes about 20-30 minutes. Sometimes a biopsy is done by making a small hole in the skull and using a needle to extract a sample of the tumor.
How are Brain Tumors Treated?
After the brain tumor has been detected, most likely by MRI or CT scans, there are several phases of treatment:
The first phase usually involves surgery. The neurosurgeons will try to remove as much tumor as possible without damaging the healthy brain. Sometimes surgery may be too great of a risk so other therapies are used first.
The second phase is the decision making and treatment planning. The neuropathologist, a doctor who specializes in looking at brain tumor cells, will examine the tumor cells from the operation to determine the type of tumor. Together, the oncologist, radiation therapist, and neurosurgeon decide on the best options and make a plan of care.
The third phase involves the actual treatment. It may be radiation therapy or chemotherapy or a combination of both. Some children may need no other therapy following surgery. The therapy is determined by many factors such as the type of tumor, its location, and your child's age.
The fourth phase is follow-up care.
