General Information About Childhood Central Nervous System Germ Cell Tumors
Key Points for This Section
- Childhood central nervous system (CNS) germ cell tumors form from germ cells.
- There are different types of childhood CNS germ cell tumors.
- The cause of most childhood CNS germ cell tumors is not known.
- Signs and symptoms of childhood CNS germ cell tumors include unusual thirst, frequent urination, early puberty, or vision changes.
- Imaging studies and tests are used to detect (find) and diagnose childhood CNS germ cell tumors.
- A biopsy may be done to be sure of the diagnosis of CNS germ cell tumor.
- Certain factors affect prognosis (chance of recovery).
Childhood central nervous system (CNS) germ cell tumors form from germ cells.
Germ cells are a type of cell that form as a fetus (unborn baby) develops. These cells later become sperm in the testicles or eggs in the ovaries. Sometimes while the fetus is forming, germ cells travel to other parts of the body and grow into germ cell tumors. Germ cells tumors that form in the brain or spinal cord are called CNS germ cell tumors.
The most common places for one or more central nervous system (CNS) germ cell tumors to form is near the pineal gland and in an area of the brain that includes the pituitary gland and the tissue just above it. Sometimes germ cell tumors may form in other areas of the brain.
This summary is about germ cell tumors that start in the central nervous system (brain and spinal cord). Germ cell tumors may also form in other parts of the body. See the PDQ summary on Childhood Extracranial Germ Cell Tumors Treatment for information on germ cell tumors that are extracranial (outside the brain).
CNS germ cell tumors usually occur in children, but may occur in adults. Treatment for children may be different than treatment for adults. See the following PDQ summaries for information about treatment for adults:
For information about other types of childhood brain and spinal cord tumors, see the PDQ summary on Childhood Brain and Spinal Cord Tumors Treatment Overview.
There are different types of childhood CNS germ cell tumors.
There are different types of CNS germ cell tumors. The type of CNS germ cell tumor depends on what the cells look like under a microscope. This summary is about the treatment of the following types of CNS germ cell tumors:
Some nongerminomas make hormones. CNS teratomas are a type of nongerminoma that does not make hormones. They may have different kinds of tissue in them, such as hair, muscle, and bone. Teratomas are described as mature or immature, based on how normal the cells look under a microscope. Sometimes teratomas are a mix of mature and immature cells.
Other types of nongerminomas include the following:
The cause of most childhood CNS germ cell tumors is not known.
Signs and symptoms of childhood CNS germ cell tumors include unusual thirst, frequent urination, early puberty, or vision changes.
- Where the tumor has formed.
- The size of the tumor.
- Whether the tumor makes hormones.
Signs and symptoms may be caused by childhood CNS germ cell tumors or by other conditions. Check with your child’s doctor if your child has any of the following:
- Being very thirsty.
- Making large amounts of urine that is clear or almost clear.
- Frequent urination.
- Bed wetting or getting up at night to urinate.
- Trouble moving the eyes or trouble seeing clearly.
- Loss of appetite.
- Weight loss for no known reason.
- Early or late puberty.
- Short stature (being shorter than normal).
- Nausea and vomiting.
- Feeling very tired.
- Having problems with school work.
Imaging studies and tests are used to detect (find) and diagnose childhood CNS germ cell tumors.
The following tests and procedures may be used:
- Physical exam and history : An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient's health habits and past illnesses and treatments will also be taken.
- Neurological exam : A series of questions and tests to check the brain, spinal cord, and nerve function. The exam checks a person’s mental status, coordination, and ability to walk normally, and how well the muscles, senses, and reflexes work. This may also be called a neuro exam or a neurologic exam.
- Visual field exam: An exam to check a person’s field of vision (the total area in which objects can be seen). This test measures both central vision (how much a person can see when looking straight ahead) and peripheral vision (how much a person can see in all other directions while staring straight ahead). The eyes are tested one at a time. The eye not being tested is covered.
- 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).
- Lumbar puncture : A procedure used to collect cerebrospinal fluid (CSF) from the spinal column. This is done by placing a needle into the spinal column. A sample of CSF is viewed under a microscope by a pathologist to check for signs of tumor cells. This procedure is also called an LP or spinal tap.
- Tumor marker tests : A procedure in which a sample of blood or cerebrospinal fluid (CSF) is checked to measure the amounts of certain substances released into the blood and CSF by organs, tissues, or tumor cells in the body. Certain substances are linked to specific types of cancer when found in increased levels in the blood. These are called tumor markers. The following tumor markers are used to diagnose some CNS germ cell tumors:
- Blood chemistry studies : A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher- or lower-than-normal) amount of a substance can be a sign of disease in the organ or tissue that makes it.
- Blood hormone studies: A procedure in which a blood sample is checked to measure the amounts of certain hormones released into the blood by organs and tissues in the body. An unusual (higher- or lower-than-normal) amount of a substance can be a sign of disease in the organ or tissue that makes it. The blood will be checked for the levels of hormones made by the pituitary gland and other glands.
A biopsy may be done to be sure of the diagnosis of CNS germ cell tumor.
If doctors think your child may have a CNS germ cell tumor, a biopsy may be done. For brain tumors, the biopsy is done by removing part of the skull and using a needle to remove a sample of tissue. Sometimes, a needle guided by a computer is used to remove the tissue sample. A pathologist views the tissue under a microscope to look for cancer cells. If cancer cells are found, the doctor may remove as much tumor as safely possible during the same surgery. The piece of skull is usually put back in place after the procedure.
Sometimes the diagnosis can be made based on the results of imaging and tumor marker tests and a biopsy is not needed.
The following test may be done on the sample of tissue that is removed:
- Immunohistochemistry : A test that uses antibodies to check for certain antigens in a sample of tissue. The antibody is usually linked to a radioactive substance or a dye that causes the tissue to light up under a microscope. This type of test may be used to tell the difference between different types of brain tumors.
Certain factors affect prognosis (chance of recovery).
The prognosis (chance of recovery) depends on the following:
- The type of germ cell tumor.
- The type and level of any tumor markers.
- Where the tumor is in the brain or in the spinal cord.
- Whether the cancer has spread within the brain and spinal cord or to other parts of the body.
- Whether the tumor is newly diagnosed or has recurred (come back) after treatment.