Germ Cell Tumors
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What Are Germ Cells?
These cells develop along the "midline" of a fetus (where the stomach and other internal organs will lie) before they settle into place in the reproductive organs.
What Are Germ Cell Tumors?
Germ cells that grow abnormally can become a tumor . Often, these tumors develop in the ovaries or testes. Because the germ cells travel along the midline to reach the reproductive organs as a fetus develops, they can sometimes settle in other places.
The most common sites for germ cell tumors outside of the reproductive organs are:
- in part of the chest between the breastplate and spine
- the tailbone
Sometimes, a tumor can develop in the middle part of the brain.
What Are the Types of Germ Cell Tumors?
Like tumors that develop in other places in the body, germ cell tumors can be benign (not cancerous) or malignant (cancerous). The most common types of germ cell tumors include:
Teratomas. These tumors are benign, but can become malignant. Teratomas are the most common type of germ cell tumor to develop in extragonadal (not in the ovary or testes) areas. Teratomas usually are treated with surgery because chemotherapy doesn't work in a benign tumor.
Germinomas. These malignant tumors are also called dysgerminomas when they're in the ovary, or seminomas when they're in the testes. They also can be in the middle part of the brain.
Yolk sac tumor (also called endodermal sinus tumor). These malignant tumors most commonly develop in the ovaries, testes, or tailbone.
Embryonal carcinoma. These malignant tumors usually develop in the testicle of an adolescent boy, but can spread ( metastasize ) to other places in the body.
Choriocarcinoma. This malignant tumor usually develops in the placenta during pregnancy and can affect both the mother and child.
What Causes Germ Cell Tumors?
The cause of most germ cell tumors isn't always known. Doctors do know that some medical conditions can make children more likely to develop these tumors. These include:
- birth defects that involve the central nervous system, genitals, urinary tract, and spine
- genetic conditions that cause missing or extra sex chromosomes
Boys with undescended testicles (testes that remain up inside the pelvis) also seem to be at a higher risk for a germ cell tumor.
What Are the Signs & Symptoms of Germ Cell Tumors?
Early on, a child with a benign or malignant germ cell tumor might have few symptoms or none at all. As the tumor grows, a mass (lump) may be felt or cause symptoms when the tumor presses against organs in the body.
Depending on where the tumor is, it can cause symptoms like:
- constipation or trouble holding pee if the tumor is in the pelvis
- leg weakness if the tumor presses on the nerves at the bottom of the spine
- a testicle that is abnormal in shape or size
How Are Germ Cell Tumors Diagnosed?
If a doctor thinks that a child might have a tumor, he or she will do a physical exam and order these tests:
Imaging studies. These might include a CT scan, MRI, X-ray, ultrasound, and a bone scan. These tests are helpful in figuring out the size and location of the tumor. They can also help show if cancer has spread to other parts of the body.
Biopsy. A biopsy is the removal of a small piece of tissue so it can be examined in a lab. This closer look by a pathologist helps the oncologist (cancer doctor) make a diagnosis and choose the right treatment. A biopsy often can be done through a laparascope using a small incision and a camera to guide the doctor's movements. Other times, a more complicated surgery may be needed because of the tumor's location.
Blood tests. Tests such as a blood count, kidney test, and liver test can check the minerals in the blood can give important information about how well the liver and other organs are working. Alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (β-HCG) tests are called tumor markers. These tests check for higher than normal levels of these proteins in the body. Higher levels can suggest a germ cell tumor. The tests also check how cancer treatment is working. These markers are also helpful after treatment to determine if the tumor has come back.
If a tumor might be related to an underlying genetic condition, genetic tests also might be done.
How Are Germ Cell Tumors Treated?
Children with benign germ cell tumors will have surgery to remove the tumor. Those with malignant tumors will first go through a process called staging.
Staging is a classification system that helps doctors figure out how far the cancer has progressed. It looks at things like:
- the size of the tumor (or tumors)
- how deep the tumor is in an organ
- whether the tumor has metastasized to nearby or distant lymph nodes or organs
This information, in addition to a child's age and overall health, helps doctors develop treatment plans. The plans may include these options, used together or alone:
Surgery. Children with malignant tumors may have surgery to remove as many of the cancerous cells as possible.
Radiation therapy. This treatment uses high-energy radiation from X-rays, gamma rays, or fast-moving subatomic particles (called particle or proton beam therapy) to target and destroy cancer cells. Radiation is not usually needed to treat germ cell tumors because they are typically very sensitive to chemotherapy.
Chemotherapy. Chemotherapy works to treat cancer throughout the body. Chemo is also the most important therapy to treat microscopic (very tiny) cells that may be hiding in other parts of the body but can't be seen on a scan or felt on exam. Often, several chemotherapy drugs are combined to attack the cancer cells in different ways.
The stress of having a child who is being treated for any type of tumor can feel overwhelming. But you're not alone. To find support, talk to your child's doctor or a hospital social worker. Many resources are available to help you and your child get through this difficult time.
Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.
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