Overview of Brain Tumors in Children
Brain tumors (also see brain tumors in adults) are the second most common cancer in children younger than 15 years (after leukemia) and the second leading cause of death from cancer.
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The most common brain tumors in children are astrocytomas. Less common brain tumors include medulloblastomas and ependymomas.
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Brain tumors can cause various symptoms, including headaches, nausea, vomiting, vision problems, listlessness, and loss of coordination or balance.
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The diagnosis is usually based on results of magnetic resonance imaging and a biopsy.
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Treatment may involve surgery, radiation therapy, chemotherapy, or a combination.
The cause of most brain tumors is usually unknown. However, high doses of radiation and certain genetic disorders (for example, neurofibromatosis) are known to cause brain tumors.
Symptoms
The first brain tumor symptoms may result from increased pressure within the skull (intracranial pressure). Pressure may be increased because the tumor blocks the flow of cerebrospinal fluid within the brain or because the tumor takes up space. Increased pressure can cause the following:
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An enlarged head (hydrocephalus) in infants and very young children
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Headaches
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Nausea and vomiting (often when the child first awakens)
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Vision problems, such as double vision
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Difficulty turning the eyes upward
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Changes in mood or consciousness level, making the child irritable, listless, confused, or drowsy
Other symptoms vary depending on the specific part of the brain in which the tumor is located.
Diagnosis
Doctors suspect a brain tumor based on symptoms.
To check for a brain tumor, doctors typically do an imaging test such as magnetic resonance imaging (MRI), which can usually detect the tumor. Computed tomography (CT) also can be done. Before MRI or CT is done, a contrast agent is usually injected into a vein (intravenously). Contrast agents are substances that make the images clearer. If a brain tumor is suspected, doctors usually remove a small piece of tissue (biopsy) to confirm the diagnosis. Sometimes, instead of removing a small piece, doctors surgically remove the entire tumor.
Sometimes a spinal tap (lumbar puncture) is done to obtain cerebrospinal fluid for examination under a microscope. This procedure is done routinely to determine whether tumor cells have spread to the cerebrospinal fluid or when the diagnosis is unclear.
Treatment
(See also Cancer Treatment Principles.)
Usually, treatment of brain tumors involves surgically removing the tumor. Then, chemotherapy, radiation therapy, or both are used. Treatment should be planned by a team of experts who have experience treating brain tumors in children. The care team may include doctors who specialize in the care and treatment of babies, children, and adolescents such as pediatric cancer specialists (oncologists), pediatric neurologists, pediatric neurosurgeons, and radiation oncologists.
When possible, the tumor is removed surgically by opening the skull (called a craniotomy). Some brain tumors can be removed with little or no damage to the brain. After surgery, MRI may be done to determine whether any of the tumor is left and, if so, how much.
If the tumor cannot be removed surgically, additional treatment is usually required. In children younger than 5 to 10 years, depending on the tumor type, chemotherapy may be used first because radiation therapy can interfere with growth and brain development. If needed, radiation therapy may be used when children are older. Chemotherapy may also have serious side effects.
If the tumor is blocking the flow of cerebrospinal fluid, a small tube (catheter) may be used to drain the cerebrospinal fluid before the tumor is surgically removed. After a local or general anesthetic is used, the tube is inserted through a tiny opening drilled in the skull, and fluid is withdrawn to reduce the pressure within the skull. The tube is connected to a gauge that measures the pressure within the skull. After a few days, the tube is removed or converted to a permanent drain (shunt—see Hydrocephalus).
Because cancer is relatively rare in children, entry into a clinical trial should be considered for all children with a brain tumor. In such trials, some children receive the standard treatment, and others receive the treatment being tested (called experimental treatment). The experimental treatment may involve new drugs, drugs used in new ways, or new surgical or radiation techniques. However, experimental treatments are not always effective, and side effects or complications may not be known.
