Childhood Brain Tumors

by National Cancer Institute

What is childhood brain tumor?

Childhood brain tumors are a diverse group of diseases characterized by the abnormal growth of tissue contained within the skull. Brain tumors can be benign (without cancer cells) or malignant (contains cancer cells). The brain controls vital functions such as memory and learning, the senses (hearing, sight, smell, taste, and touch), and emotion. It also controls other parts of the body, including muscles, organs, and blood vessels. Other than leukemia and lymphoma, brain tumors are the most common type of cancer that occurs in children.

This PDQ treatment information summary refers only to tumors that originate in the brain (primary brain tumors). Metastatic brain tumors, which are secondary tumors formed by cancer cells that begin in other parts of the body and spread to the brain, are not included. Brain tumors can occur in both children and adults; however, treatment may be different for adults than for children. (Refer to the PDQ summary on Adult Brain Tumor Treatment 1 for more information.)

If your child has symptoms that may be caused by a brain tumor, his or her doctor may order a computed tomographic (CT) scan, a diagnostic test that uses computers and x-rays to create pictures of the body. A magnetic resonance imaging (MRI) scan, a diagnostic test similar to a CT scan but which uses magnetic waves instead of x-rays, may also be performed.

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. This is called a biopsy. Sometimes a biopsy is done by making a small hole in the skull and using a needle to extract a sample of the tumor.

There are many types of brain tumors that occur in children. Treatment and chance of recovery (prognosis) depend on the type of tumor, its location within the brain, the extent to which it has spread, and your child's age and general health.

Stage Explanation

Types of childhood brain tumor

Once childhood brain tumor is detected, additional tests will be performed to determine the type of tumor. If a biopsy specimen is taken, the tumor cells will be examined carefully under a microscope to see how different they appear from normal cells. This will determine the grade of the tumor. The grade of a tumor is determined by microscopic examination of its cells to see how similar the cells are to normal cells. Cells from higher-grade, more abnormal-looking tumors usually grow faster and are more malignant than cells from lower-grade tumors. Your child's doctor needs to know the type and grade of tumor in order to plan treatment.

There is no staging for childhood brain tumors. Brain tumors are grouped according to their location within the brain and the appearance and behavior of the tumor tissue. The following groupings are used for childhood brain tumors:

Infratentorial tumors

Infratentorial tumors are those that occur in the lower part of the brain. Tumors found in this region include:

Medulloblastoma

Cerebellar astrocytoma

Infratentorial ependymoma

Ependymal tumors are tumors that begin in the ependyma, the cells that line the hollow cavities within the brain (called ventricles) which are filled with cerebrospinal fluid). The growth of ependymal tumors can obstruct the flow of the cerebrospinal fluid through the brain and spinal cord. Infratentorial ependymomas begin in the lower part of the brain. These tumors may spread via the cerebrospinal fluid to other areas of the brain and spinal cord. Brain stem glioma

Supratentorial tumors

Supratentorial tumors are those that occur in the upper part of the brain. Common supratentorial tumors include: Cerebral astrocytoma

Supratentorial ependymoma

Ependymal tumors are tumors that begin in the ependyma, the cells that line the hollow cavities within the brain (called ventricles) which are filled with cerebrospinal fluid. The growth of ependymal tumors can obstruct the flow of the cerebrospinal fluid through the brain. Supratentorial ependymomas begin in the upper part of the brain. These tumors may spread to other areas of the brain and spinal cord, depending on their grade.

Craniopharyngioma

Craniopharyngiomas are tumors that generally occur just above the pituitary gland. Located at the bottom of the brain, the pituitary gland is about the size of a pea and controls many vital functions. Craniopharyngiomas do not spread, but may interfere with important structures near them, causing serious problems.

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