What Is It?
A brain tumor is a mass of abnormally growing cells in the brain or skull. It can be either benign (noncancerous and unlikely to spread) or malignant (cancerous and likely to spread). Whether benign or malignant, all brain tumors are serious because a growing tumor eventually will compress and damage other structures in the brain.
There are two categories of brain tumors: primary and secondary. Primary tumors originate in brain tissue, can be benign or malignant, and are classified by the tissue in which they begin:
- Gliomas, the most common primary tumors, start in the brain’s glial (supportive) tissue. Gliomas include astrocytomas, glioblastomas, oligodendroglial tumors and ependymal tumors.
- Medulloblastomas come from early embryonic cells and more commonly occur in children.
- Meningiomas are related to the type of cells in the lining of membranes surrounding the brain and spinal cord. They are more commonly benign, but can be recurrent or malignant.
- Glioblastoma multiforme is a higher-grade tumor that can arise from lower-grade gliomas.
- Lymphoma arises from lymphocyte cells, usually in other parts of the body, but also can occur in just the brain or spinal cord.
A brain tumor also can be cancer that has spread to the brain from another part of the body. These are called secondary tumors, and most commonly come from the lungs or breast. When this happens, the cancer is the same as the original cancer. For example, lung cancer that spreads to the brain is known as metastatic lung cancer because the tumor’s cells resemble abnormal lung cells, rather than abnormal brain cells. Secondary brain tumors are more common than primary tumors. They occur in approximately 25 percent of people who have cancer elsewhere.
More than 17,000 people in the United States are diagnosed with brain tumors each year, according to the American Cancer Society. Although brain tumors can occur at any age, they most commonly appear in adults 40 to 70 years old and children 3 to 12 years of age.
The symptoms of a brain tumor often are the same as those of other diseases and also may develop gradually, so they often are overlooked for a long time before diagnosis.
Although a brain tumor rarely causes headache, headaches in someone with no previous history of them should be evaluated by a professional. Headaches from a brain tumor tend to be worse upon waking and ease during the day. Other symptoms of brain tumor include:
- Vomiting and nausea
- Weakness in the arms or legs
- Speech difficulties or changes
- Lack of coordination in walking
- Changes in vision or abnormal eye movements
- Memory or personality changes
The specific symptoms of a brain tumor depend on its size and location within the brain. They can be caused by a number of factors, including:
- Increased pressure inside the skull
- Damage to vital tissue
- Swelling and fluid buildup (edema) around the tumor
- Hydrocephalus, sometimes called “water on the brain,” which results when the flow of cerebrospinal fluid is blocked and builds up in the brain
Your doctor will ask you about your symptoms and about your personal and family medical history. He or she will do a complete physical and neurological examination. The neurological examination looks at reflexes, coordination, sensation, pain response and muscle strength. By looking into your eyes with a lighted scope, your doctor can check for possible signs of increased pressure or swelling. Depending on your symptoms or the physical exam, your doctor may order one or more of the following tests:
- Computed tomography (CT) scan — This creates a cross-sectional view of the brain using an X-ray camera that rotates around the body. A dye sometimes is injected into a vein prior to the scan to make it easier to see the tumor.
- Magnetic resonance imaging (MRI) — This gives a picture of the brain using a powerful magnet, a radiowave transmitter and computer. An MRI can be better at looking at some parts of the brain than a CT scan. A special dye may be injected into the blood to enhance the images. A magnetic resonance angiogram is similar to an MRI scan but looks specifically at the flow of blood in arteries. This is helpful for finding aneurysms or better defining tumors.
- Lumbar puncture (spinal tap) — A sample of spinal fluid is taken from the lower back through a needle. The fluid can be checked for signs of infection or cancer cells. If you have a headache, it is especially important that this test be done to check for infectious meningitis. This is usually done after the doctor has seen the CT or MRI scan. This test is also important if the diagnosis is brain lymphoma. The treatment is different for brain lymphoma that has spread to the spinal fluid.
If a possible tumor is found, you might have one of the following tests before a biopsy or surgery is performed:
- Magnetic resonance spectroscopy — This test is similar to an MRI but picks up signals from different substances in the body, which sometimes gives a clearer image of a tumor. The use of this method for brain tumors is still experimental, and it is not used routinely.
- Positron emission tomography (PET) scan — This test identifies a tumor by how it uses sugar or other substances differently than normal brain tissue. It is used more to test the success of treatments by distinguishing a tumor from scar tissue. For this test, a very low dose of radioactive sugar is injected into a vein.
- Cerebral angiography — This sometimes is used to further evaluate the size and site of the tumor if surgery is planned. It is an X-ray of the veins and arteries that uses a special dye to define the outlines of the blood vessel.
Sometimes, brain tumors are cancer that has spread from other parts of the body. If this is suspected, radiology tests also may be done of other organs.
Once a tumor is identified, a biopsy is needed to identify the type of tumor. In a biopsy, a small sample of tissue is removed and examined in a laboratory. A neurosurgeon can use CT, MRI and computer stereotactic techniques to carefully guide a needle to the site of the tumor and take a small sample of tissue in the operating room. He or she also may decide to take biopsies at the same time that surgery is done to remove as much of the tumor as possible.
Once it develops, a brain tumor will continue growing until it is treated. Without treatment, permanent brain damage or death can result. Many types of brain tumors can lead to death despite the best treatment efforts.
There is no way to predict or prevent the development of brain tumors. As more is learned about the causes of brain tumors, more can be done to help prevent them. Among the areas of investigation are genetic and hereditary factors, environmental exposure to certain chemicals, and exposure to certain viruses.
Treatment for a brain tumor depends upon its size, location and type as well as the person’s health and age. The team of doctors involved in the treatment planning may include a neurologist, oncologist and neurosurgeon. The main treatment methods include surgery, radiation therapy and chemotherapy. Many times, a combination of treatments is used, such as surgery and radiation therapy. Prior to treatment, corticosteroid drugs may be given to reduce swelling of the brain tissue, and anticonvulsant drugs may also be prescribed to prevent or control tumor-related seizures.
When possible, surgery is the first line of treatment and can remove some benign and malignant brain tumors successfully. Meningiomas, some ependymomas, gangliogliomas and cerebellar astrocytomas are more likely to be cured by surgery than are other types of brain tumors. Even if the entire tumor cannot be removed because it is attached to vital brain tissue, doctors often will take out as much as possible to help to reduce pressure and relieve symptoms.
Some tumors cannot be removed or surgery is considered risky. In such cases, a biopsy may be done to help determine whether other treatments may be more effective. Stereotactic surgical techniques, which use computers and radiographic devices to create a three-dimensional image of the brain, can be used to biopsy or remove tumors, implant local treatments or help physicians navigate during surgery. Stereotactic surgery is especially useful in reaching tumors located deep within the brain and also can help to pinpoint the tumor’s edges so that less normal brain tissue is removed. This lowers the chance for side effects from brain injury during the surgery.
Radiation therapy, which uses high-powered rays to kill cancer cells, is often used after surgery to help rid the area of any remaining cancer cells or to destroy parts of the tumor that could not be removed by surgery. Because high-dose radiation can damage normal brain tissue, the radiation oncologist tries to target high doses of radiation to the tumor and the lowest possible doses to surrounding brain areas. Radiation also can be given by placing radioactive material directly into the tumor.
Radiation alone can cure some forms of brain cancer. For instance, up to one half of all medulloblastomas are cured by radiation. In addition, radiation appears to be most effective against rapidly growing cells, making high-grade (fast-growing) tumors more responsive to radiation therapy than low-grade (slow-growing) tumors. Radiation therapy also is used when surgery is not an option.
Chemotherapy may involve one or a combination of anticancer drugs, usually taken orally or by injection. Lymphomas of the brain respond very well to chemotherapy and radiation therapy.
In addition, research into new treatment methods, and clinical trials of these methods, are continuing. New types and schedules of radiation therapy, new drug combinations, new anticancer drugs, and new combinations of radiation and chemotherapy are being researched. Studies also are exploring the effectiveness of placing cancer-fighting drugs and radioactive disks directly into a tumor.
When To Call A Professional
Call a doctor for an immediate evaluation if you have new seizures, new and severe headaches, unexplained drowsiness, sudden changes in vision or speech difficulties. Also, if you have unexplained weakness, or memory or personality changes, you should call your doctor.
Early detection and treatment offer the best chance of recovery from both noncancerous and cancerous brain tumors. The prognosis also depends on the type of tumor, its size and location, the person’s age, the extent of any surgery and how the tumor has affected the person’s ability to function. In general, lower-grade tumors have a better prognosis. Meningiomas also tend to have a good prognosis because they are usually not cancerous and can be removed more easily. High-grade astrocytomas and glioblastoma multiforme tend to have a poorer outlook, but there are exceptions.
Diseases and Conditions Center
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.