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.
- Childhood CNS germ cell tumors are grouped into germinomas, teratomas, and nongerminomas.
- The cause of most childhood CNS germ cell tumors is not known.
- Possible signs 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 central nervous system germ cell tumors.
- Certain factors affect prognosis (chance of recovery) and treatment options.
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).
The most common place for one or more central nervous system (CNS) germ cell tumors to form is near the pineal gland and in an area that includes the pituitary gland and the tissue just above it. Sometimes germ cell tumors may form in other areas of the brain.
CNS germ cell tumors can occur in both children and adults; treatment for children may be different than treatment for adults. See the following PDQ summaries for more information about the treatment of adults:
For more information about the different types of childhood brain and spinal cord tumors, see the PDQ summary on Childhood Brain and Spinal Cord Tumors Treatment Overview.
CNS teratomas may contain different kinds of cells that can grow into tissues, such as hair, muscle, and bone, within the tumor. Teratomas are described as mature or immature, based on how normal the cells look under a microscope. Teratomas are sometimes a mix of mature and immature cells.
Some nongerminomas make hormones. The following kinds of tumors are nongerminomas:
- Choriocarcinoma: These tumors make the hormone beta-human chorionic gonadotropin (β-hCG).
- Embryonal carcinoma: These tumors do not make hormones.
- Yolk sac tumor: These tumors make the hormone alpha-fetoprotein (AFP).
- Mixed germ cell tumor: A tumor that is made of more than one kind of germ cell.
These and other symptoms may be caused by childhood CNS germ cell tumors. The symptoms may be different depending on where the tumor is, the size of the tumor, and whether the tumor makes hormones. Check with your child’s doctor if you see any of the following problems in your child:
- Being very thirsty.
- Making large amounts of clear or almost clear urine.
- Frequent urination.
- Bed wetting or getting up at night to urinate.
- Problems moving eyes or loss of vision.
- Loss of appetite.
- Weight loss for no known reason.
- Early or late puberty.
- Short stature (being shorter than normal).
- Nausea and vomiting.
- Doing poorly in school.
Other conditions may cause the same symptoms.
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).
- Biopsy : The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer. In some cases, the tumor is removed during surgery and a biopsy may be done.
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 cancer.
- 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: If there are no tumor markers in the blood or CSF, a biopsy of the tumor is done.
- 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.
The prognosis (chance of recovery) and treatment options depend on the following:
- The type of germ cell tumor.
- The level of tumor marker.
- Where the tumor is in the brain or 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.