Key Points for This Section

Childhood medulloblastoma is a disease in which benign (noncancer) or malignant (cancer) cells form in the tissues of the brain. The cause of most childhood brain tumors is unknown. The signs of childhood medulloblastoma vary and often depend on the child’s age and where the tumor is located. Tests that examine the brain and spinal cord are used to detect (find) childhood medulloblastoma. Childhood medulloblastoma is diagnosed and removed in surgery. Certain factors affect prognosis (chance of recovery) and treatment options.

Note: This PDQ summary contains content that is included in the new PDQ Childhood Central Nervous System Embryonal Tumors summary. A health professional version of the Childhood Central Nervous System Embryonal Tumors summary is currently available on the National Cancer Institute (NCI) Web site and a patient version is coming soon.

In the near future, the health professional and patient versions of the PDQ Childhood Medulloblastoma summary will be removed from the NCI Web site.

Childhood medulloblastoma is a disease in which benign (noncancer) or malignant (cancer) cells form in the tissues of the brain.

Childhood medulloblastoma (tumor) usually forms in the cerebellum, which is at the lower back of the brain. The cerebellum is the part of the brain that controls movement, balance, and posture. Childhood medulloblastoma may also be called primitive neuroectodermal tumor (PNET).

About 1 out of 5 childhood brain tumors are medulloblastomas. Although cancer is rare in children, brain tumors are the most common type of childhood cancer other than leukemia and lymphoma.

This summary refers to the treatment of primary brain tumors (tumors that begin in the brain). Treatment for metastatic brain tumors, which are tumors formed by cancer cells that begin in other parts of the body and spread to the brain, is not discussed in this summary. See the PDQ treatment summary on Childhood Brain and Spinal Cord Tumors Treatment Overview ¹ for information about the different types of childhood brain and spinal cord tumors.

Brain tumors can occur in both children and adults; however, treatment for children may be different than treatment for adults. (See the PDQ treatment summary on Adult Brain Tumors ² for more information.)

The cause of most childhood brain tumors is unknown.

The signs of childhood medulloblastoma vary and often depend on the child’s age and where the tumor is located.

The following symptoms and others may be caused by medulloblastoma. Other conditions may cause the same symptoms. A doctor should be consulted if any of these problems occur:

• Loss of balance, trouble walking, worsening handwriting, or slow speech.
• Morning headache or headache that goes away after vomiting.
• Nausea and vomiting.
• Unusual sleepiness or change in energy level.
• Change in personality or behavior.
• Unexplained weight loss or weight gain.

Tests that examine the brain and spinal cord are used to detect (find) childhood medulloblastoma.

The following tests and procedures may be used:

• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
• MRI (magnetic resonance imaging) with gadolinium: A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the brain and spinal cord. A substance called gadolinium is injected into a vein. The gadolinium collects around the cancer cells so they show up brighter in the picture. This procedure is also called nuclear magnetic resonance imaging (NMRI).

Childhood medulloblastoma is diagnosed and removed in surgery.

If a brain tumor is suspected, a biopsy is done by removing part of the skull and using a needle to remove a sample of the tumor tissue. A pathologist views the tissue under a microscope to look for cancer cells. If cancer cells are found, the doctor will remove as much tumor as possible during the same surgery.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) and treatment options depend on:

• The age of the child when the tumor is found.
• The location of the tumor.
• The amount of tumor remaining after surgery.
• Whether the cancer has spread to other parts of the central nervous system (brain and spinal cord), or to other parts of the body, such as the bones.
• Whether the tumor has just been diagnosed or has recurred (come back).

Glossary Terms

The removal of cells or tissues for examination by a pathologist. The pathologist may study the tissue under a microscope or perform other tests on the cells or tissue. There are many different types of biopsy procedures. The most common types include: (1) incisional biopsy, in which only a sample of tissue is removed; (2) excisional biopsy, in which an entire lump or suspicious area is removed; and (3) needle biopsy, in which a sample of tissue or fluid is removed with a needle. When a wide needle is used, the procedure is called a core biopsy. When a thin needle is used, the procedure is called a fine-needle aspiration biopsy.

The growth of abnormal cells in the tissues of the brain. Brain tumors can be benign (non-cancerous) or malignant (cancerous).

A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

CNS. The brain and spinal cord. Also called CNS.

The portion of the brain in the back of the head between the cerebrum and the brain stem. The cerebellum controls balance for walking and standing, and other complex motor functions.

A dye or other substance that helps show abnormal areas inside the body. It is given by injection into a vein, by enema, or by mouth. Contrast material may be used with x-rays, CT scans, MRI, or other imaging tests.

Computed tomography scan. A series of detailed pictures of areas inside the body taken from different angles; the pictures are created by a computer linked to an x-ray machine. Also called computed tomography scan, computerized tomography, computerized axial tomography scan, and CAT scan.

The process of identifying a disease by the signs and symptoms.

A substance that is being studied in the treatment of cancer. It may make tumor cells more sensitive to radiation therapy, improve tumor images using magnetic resonance imaging (MRI), and kill cancer cells. It is a type of metalloporphyrin complex. Also called motexafin gadolinium.

Use of a syringe and needle to push fluids or drugs into the body; often called a "shot."

Cancer that starts in blood-forming tissue such as the bone marrow and causes large numbers of blood cells to be produced and enter the bloodstream.

Cancer that begins in cells of the immune system. There are two basic categories of lymphomas. One kind is Hodgkin lymphoma, which is marked by the presence of a type of cell called the Reed-Sternberg cell. The other category is non-Hodgkin lymphomas, which includes a large, diverse group of cancers of immune system cells. Non-Hodgkin lymphomas can be further divided into cancers that have an indolent (slow-growing) course and those that have an aggressive (fast-growing) course. These subtypes behave and respond to treatment differently. Both Hodgkin and non-Hodgkin lymphomas can occur in children and adults, and prognosis and treatment depend on the stage and the type of cancer.

A malignant brain tumor that begins in the lower part of the brain and that can spread to the spine or to other parts of the body. Medulloblastomas are a type of primitive neuroectodermal tumor (PNET).

Cancer that has spread from the place in which it started to other parts of the body.

A procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body. These pictures can show the difference between normal and diseased tissue. MRI makes better images of organs and soft tissue than other scanning techniques, such as computed tomography (CT) or x-ray. MRI is especially useful for imaging the brain, the spine, the soft tissue of joints, and the inside of bones. Also called magnetic resonance imaging, nuclear magnetic resonance imaging, and NMRI.

A feeling of sickness or discomfort in the stomach that may come with an urge to vomit. Nausea is a side effect of some types of cancer therapy.

A part of the body that performs a specific function. For example, the heart is an organ.

A doctor who identifies diseases by studying cells and tissues under a microscope.

PDQ is an online database developed and maintained by the National Cancer Institute. Designed to make the most current, credible, and accurate cancer information available to health professionals and the public, PDQ contains peer-reviewed summaries on cancer treatment, screening, prevention, genetics, complementary and alternative medicine, and supportive care; a registry of cancer clinical trials from around the world; and directories of physicians, professionals who provide genetics services, and organizations that provide cancer care. Most of this information, and more specific information about PDQ, can be found on the NCI's Web site at http://www.cancer.gov/cancertopics/pdq. Also called Physician Data Query.

The original tumor.

The likely outcome or course of a disease; the chance of recovery or recurrence.

To come back or to return.

A column of nerve tissue that runs from the base of the skull down the back. It is surrounded by three protective membranes, and is enclosed within the vertebrae (back bones). The spinal cord and the brain make up the central nervous system, and spinal cord nerves carry most messages between the brain and the rest of the body.

A procedure to remove or repair a part of the body or to find out whether disease is present. An operation.

An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.

A group or layer of cells that work together to perform a specific function.

An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancerous), or malignant (cancerous). Also called neoplasm.

A blood vessel that carries blood to the heart from tissues and organs in the body.

To eject some or all of the contents of the stomach through the mouth.

A type of high-energy radiation. In low doses, x-rays are used to diagnose diseases by making pictures of the inside of the body. In high doses, x-rays are used to treat cancer.