What Are Germ Cell Tumors?
Germ cell tumors that develop in the brain or spinal cord are also called CNS (central nervous system) germ cell tumors. Most germ cell tumors appear in the ovaries (ovarian tumors) or testes (testicular tumors), but they can also get “trapped” in the brain during the fetal period. They can be benign (noncancerous) or malignant (cancerous).
- The two main types of germ cell tumors of the brain are germinomas and non-germinomatous tumors. If they include aspects of both, they are called mixed germ cell tumors.
- Germ cell tumors of the brain are rare, accounting for approximately 4 percent of brain tumors in children.
- Around 50 percent occur in children between 10 to 15 years old.
- They are most commonly found in or around the pituitary and pineal glands.
At Dana-Farber/Boston Children's Cancer and Blood Disorders Center, your child will receive care at one of the largest and most experienced pediatric brain tumor treatment programs in the world. Within the Childhood Brain Tumor Center, our specialists have extensive expertise in treating all types of brain tumors, including germ cell tumors.
Causes and Symptoms of Childhood Germ Cell Tumors of the Brain
Researchers don’t know the cause of germ cell tumors. Usually, germ cells migrate to the gonads during fetal development. They become an egg in the female ovaries or sperm in the male testes. However, when these germ cells don't move to the right area, they can become trapped in the brain and multiply in areas where they shouldn't.
It's important to understand that these and other brain tumors most often occur with no known cause. There's nothing that you could have done or avoided doing that would have prevented the tumor from developing.
Symptoms typically depend on where they have developed in the brain. For tumors in the pineal gland region, children can have the following symptoms:
- Hydrocephalus (swelling of the brain)
- Behavioral or cognitive changes
- Uncoordinated body movement (ataxia)
- Vision changes, including double vision and difficulty looking up
For tumors in the suprasellar or pituitary gland region, common symptoms include:
- Diabetes insipidus (an uncommon disorder characterized by intense thirst and the passing of large amounts of urine)
- Delayed puberty
- Early (precocious) puberty
- Stunted growth
- Vision changes, including loss of peripheral vision or decrease in vision
How We Diagnose and Classify Childhood Germ Cell Tumors of the Brain
Effective treatment starts with an accurate diagnosis. Doctors typically confirm a diagnosis using a combination of physical and neurological exams, advanced imaging studies, blood tests, and lumbar puncture.
Successfully treating your child's germ cell tumor depends on identifying the tumor type and location. We classify germ cell tumors of the brain into two main types:
- Germinomas: These are pure germ cell tumors. They respond well to treatment.
- Non-germinomatous tumors: These tumors secrete chemicals into the spinal fluid and bloodstream. They require more intensive treatment than germinomas.
- There are several sub-types of non-germinomatous germ cell tumors, including teratomas, choriocarcinomas, endodermal sinus tumors (yolk sac tumors), embryonal carcinomas, and mixed tumors.
After we complete all diagnostic testing, a team of pediatric tumor experts comes together to decide on the best treatment plan for your child. We meet with you and your family to discuss our treatment recommendations and answer any questions.
How We Treat Childhood Germ Cell Tumors of the Brain
Your child's treatment plan will depend on their age, health, and medical history, as well as the tumor’s characteristics.
Treatments we offer include:
When a tumor causes blockage of cerebral spinal fluid flow, our surgeons may perform one of two procedures to relieve symptoms of hydrocephalus, the buildup of fluid inside the skull.
Tumors that are unlikely to spread receive radiation to the tumor and the area surrounding it. If the tumor is likely to spread beyond its original location, we may recommend radiation to other parts of the brain and spinal cord. If the tumor has already spread, we deliver radiation to the whole brain and spinal cord.
- Surgery: We initially use surgery to biopsy the tumor and form a complete diagnosis. Depending on the germ cell tumor type, we may recommend further surgery to remove as much of the tumor as possible.
- Endoscopic third ventriculostomy (ETV): In an endoscopic third ventriculostomy, surgeons create a small hole that allows fluid to flow around the blockage.
- Ventriculo-peritoneal shunt (VP shunt): In some cases, children may have an alternative procedure in which a tube is placed in the ventricles to the abdomen to drain excess fluid into the stomach.
- Chemotherapy: Chemotherapy treatment involves medications that interfere with a cancer cell’s ability to grow or reproduce. Doctors use it to shrink tumors and eliminate remaining cancer cells. Different groups of chemotherapy drugs work in different ways. They are generally systemic treatments. Your child may receive chemotherapy in the following ways:
- Orally, as a pill to swallow
- Intramuscularly, as an injection into the muscle or under the skin
- Intravenously (IV), as a direct injection into the bloodstream
- Intrathecally, as a direct injection into the spinal fluid
- Radiation therapy: Doctors may use radiation therapy, which involves using high-energy waves to shrink tumors or damage and destroy cancer cells.
Children with germ cell tumors of the brain receive ongoing care in our pediatric cancer survivorship programs, including the Stop & Shop Family Pediatric Neuro-Oncology Outcomes Clinic for pediatric brain tumor survivors. We provide everything from ongoing medical care to psychosocial and nutritional support. Our goal is to support your child's physical, mental, and emotional health as they grow.