General Information About Childhood Extracranial Germ Cell Tumors
KEY POINTS
Childhood extracranial germ cell tumors form from germ cells in parts of the body other than the brain.
Childhood extracranial germ cell tumors may be benign or malignant.
There are three types of extracranial germ cell tumors.
Teratomas
Malignant Germ Cell Tumors
Mixed Germ Cell Tumors
Childhood extracranial germ cell tumors are grouped as gonadal or extracranial extragonadal.
Gonadal Germ Cell Tumors
Extragonadal Extracranial Germ Cell Tumors
The cause of most childhood extracranial germ cell tumors is unknown.
Having certain inherited disorders can increase the risk of an extracranial germ cell tumor.
Signs of childhood extracranial germ cell tumors depend on the type of tumor and where it is in the body.
Imaging studies and blood tests are used to detect (find) and diagnose childhood extracranial germ cell tumors.
Certain factors affect prognosis (chance of recovery) and treatment options.
Childhood extracranial germ cell tumors form from germ cells in parts of the body other than the brain.
A germ cell is a type of cell that forms 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 parts of the body where they should not be and grow into a germ cell tumor. The tumor may form before or after birth.
This summary is about germ cell tumors that form in parts of the body that are extracranial (outside the brain). Extracranial germ cell tumors usually form in the following areas of the body:
Testicles.
Ovaries.
Sacrum or coccyx (bottom part of the spine).
Retroperitoneum (the back wall of the abdomen).
Mediastinum (area between the lungs).
ENLARGEExtracranial germ cell tumors form in parts of the body other than the brain. This includes the testicles, ovaries, sacrum (lower part of the spine), coccyx (tailbone), mediastinum (area between the lungs), and retroperitoneum (the back wall of the abdomen).
Extracranial germ cell tumors are most common in adolescents.
See the PDQ summary on Childhood Central Nervous System Germ Cell Tumors Treatmentfor information on intracranial (inside the brain) germ cell tumors.
Childhood extracranial germ cell tumors may be benign or malignant.
Extracranial germ cell tumors may be benign (noncancer) or malignant (cancer).
There are three types of extracranial germ cell tumors.
Extracranial germ cell tumors are grouped into teratomas, malignant germ cell tumors, and mixed germ cell tumors:
Teratomas
There are two main types of teratomas:
Mature teratomas. These tumors are the most common type of extracranial germ cell tumor. Mature teratomas are benign tumors and not likely to become cancer. They usually occur in the sacrum or coccyx (bottom part of the spine) in newborns or in the testicles or ovaries at the start of puberty. The cells of mature teratomas look almost like normal cells under a microscope. Some mature teratomas release enzymes or hormones that cause signs and symptoms of disease.
Immature teratomas. These tumors usually occur in the sacrum or coccyx in newborns or the ovaries at the start of puberty. They have cells that look very different from normal cells under a microscope. Immature teratomas may be cancer and spread to other parts of the body. They often have several different types of tissue in them, such as hair, muscle, and bone. Some immature teratomas release enzymes or hormones that cause signs and symptoms of disease.
Malignant Germ Cell Tumors
Malignant germ cell tumors are cancer. There are two main types of malignant germ cell tumors:
Seminomatous germ cell tumors. These tumors make a hormone called beta-human chorionic gonadotropin (β-hCG). There are three types of seminomatous germ cell tumors:
Seminomas form in the testicle in boys.
Dysgerminomas form in the ovary in girls.
Germinomas form in areas of the body that are not the ovary or testicle, such as the mediastinum.
Non-seminomatous germ cell tumors. There are five types of non-seminomatous germ cell tumors:
Yolk sac tumors make a hormone called alpha-fetoprotein (AFP). They can form in the ovary, testicle, or other areas of the body.
Choriocarcinomas make a hormone called beta-human chorionic gonadotropin (β-hCG). They can form in the ovary, testicle, or other areas of the body.
Embryonal carcinomas may make a hormone called β-hCG and/or a hormone called AFP. They can form in the testicle or other areas of the body, but not in the ovary.
Gonadoblastomas.
Teratoma and yolk sac tumors.
Mixed Germ Cell Tumors
Mixed germ cell tumors are made up of at least two types of malignant germ cell tumor. They can form in the ovary, testicle, or other areas of the body.
Childhood extracranial germ cell tumors are grouped as gonadal or extracranial extragonadal.
Malignant extracranial germ cell tumors are tumors that form outside the brain. They are gonadal or extragonadal.
Gonadal Germ Cell Tumors
Gonadal germ cell tumors form in the testicles in boys or ovaries in girls.
Testicular germ cell tumors. Testicular germ cell tumors are divided into two main types, seminoma and nonseminoma.
Seminomas make a hormone called beta-human chorionic gonadotropin (β-hCG).
Nonseminomas are usually large and cause signs or symptoms. They tend to grow and spread more quickly than seminomas.
Testicular germ cell tumors usually occur before the age of 4 years or in adolescents and young adults. Testicular germ cell tumors in adolescents (aged 11 years and older) and young adults are different from those that form in early childhood.
Ovarian germ cell tumors. Ovarian germ cell tumors are more common in adolescent girls and young women. Most ovarian germ cell tumors are benign teratoma (dermoid cysts). Sometimes immature teratomas, dysgerminomas, yolk sac tumors, and mixed germ cell tumors (cancer) occur.
Extragonadal Extracranial Germ Cell Tumors
Extragonadal extracranial germ cell tumors form in areas other than the brain, testicles, or ovaries.
Most extragonadal extracranial germ cell tumors form along the midline of the body. This includes the following:
Sacrum (the large, triangle-shaped bone in the lower spine that forms part of the pelvis).
Coccyx (the small bone at the bottom of the spine, also called the tailbone).
Mediastinum (the area between the lungs).
Back of the abdomen.
Neck.
In younger children (aged younger than 11 years), extragonadal extracranial germ cell tumors usually occur at birth or in early childhood. Most of these tumors are teratomas in the sacrum or coccyx.
In older children, adolescents, and young adults (aged 11 years and older), extragonadal extracranial germ cell tumors are often in the mediastinum.
The cause of most childhood extracranial germ cell tumors is unknown.
Having certain inherited disorders can increase the risk of an extracranial germ cell tumor.
Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer. Talk with your child’s doctor if you think your child may be at risk.
Possible risk factors for extracranial germ cell tumors include the following:
Having certain genetic syndromes:
Klinefelter syndrome may increase the risk of germ cell tumors in the mediastinum.
Swyer syndrome may increase the risk of germ cell tumors in the testicles or ovaries.
Turner syndrome may increase the risk of germ cell tumors in the ovaries.
Signs of childhood extracranial germ cell tumors depend on the type of tumor and where it is in the body.
Different tumors may cause the following signs and symptoms. Other conditions may cause these same signs and symptoms. Check with a doctor if your child has any of the following:
A lump in the neck, abdomen or lower back.
A painless lump in the testicle.
Pain in the abdomen.
Fever.
Constipation.
In females, no menstrual periods.
In females, unusual vaginal bleeding.
Imaging studies and blood tests are used to detect (find) and diagnose childhood extracranial 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. The testicles may be checked for lumps, swelling, or pain. A history of the patient’s health habits and past illnesses and treatments will also be taken.
Serum tumor marker test : A procedure in which a sample of blood is checked to measure the amounts of certain substances released into the blood 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.
Most malignant germ cell tumors release tumor markers. The following tumor markers are used to detect extracranial germ cell tumors:
Alpha-fetoprotein (AFP).
Beta-human chorionic gonadotropin (β-hCG).
For testicular germ cell tumors, blood levels of the tumor markers help show if the tumor is a seminoma or nonseminoma.
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.
Chest x-ray : An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
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. ENLARGEComputed tomography (CT) scan of the abdomen. The child lies on a table that slides through the CT scanner, which takes x-ray pictures of the inside of the abdomen.
MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI). ENLARGEMagnetic resonance imaging (MRI) of the abdomen. The child lies on a table that slides into the MRI scanner, which takes pictures of the inside of the body. The pad on the child’s abdomen helps make the pictures clearer.
Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. The picture can be printed to be looked at later. ENLARGEAbdominal ultrasound. An ultrasound transducer connected to a computer is pressed against the skin of the abdomen. The transducer bounces sound waves off internal organs and tissues to make echoes that form a sonogram (computer picture).
Biopsy : The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer. Sometimes an incisional biopsy or needle biopsy is done. Sometimes the tumor is removed during surgery and then a biopsy is done.
The following tests may be done on the sample of tissue that is removed:
Cytogenetic analysis : A laboratory test in which cells in a sample of tissue are viewed under a microscope to look for certain changes in the chromosomes.
Immunohistochemistry : A test that uses antibodies to check for certain antigensin 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.
Certain factors affect prognosis (chance of recovery) and treatment options.
The prognosis (chance of recovery) and treatment options depend on the following:
The patient’s age and general health.
The stage of the cancer (whether it has spread to nearby areas, lymph nodes, or to other places in the body).
Where the tumor first began to grow.
How well the tumor responds to treatment (lower AFP and β-hCG levels).
The type of germ cell tumor.
Whether the tumor can be completely removed by surgery.
Whether the cancer has just been diagnosed or has recurred (come back).
The prognosis for childhood extracranial germ cell tumors, especially ovarian germ cell tumors, is good.
