What are central nervous system (CNS) germ cell tumors?

Central nervous system (CNS) germ cell tumors are a group of brain tumors that include germinomas and non-germinomatous germ cell tumors (NGGCT). They are thought to arise during early development of the fetus when germ cells, the cells that later become sperm and egg cells, migrate to the brain where they begin to form tumors.

CNS germ cell tumors typically form near the pineal gland or the pituitary gland, though they can form in other parts of the brain. The symptoms they produce are caused by the pressure they put as they grow on these glands and nearby nerves and brain tissue.

Causes of germ cell tumors

The cause of most CNS germ cell tumors is not known.

Signs and symptoms of germ cell tumors

Symptoms of CNS germ cell tumors may include:

• Excessive thirst and urination
• Vision problems, such as
  • Trouble moving the eyes
  • Uncontrolled side-to-side eye movement (nystagmus)
  • Reduced vision in one or both eyes or reduced peripheral vision
  • Double vision
• Slowed growth or short stature
• Loss of appetite
• Weight loss
• Early or delayed puberty
• Less frequent menstrual periods
• Low energy, listlessness or unusual sleepiness
• Headache
• Nausea and vomiting
• Trouble concentrating, problems with school work

Testing and diagnosis for germ cell tumors

Your doctor will usually begin with a physical exam and with questions about any symptoms you may have noticed.

• Height and weight will be charted to look for changes in growth patterns.
• The doctor may check for lumps.

If eye problems, either abnormal eye movement or poor vision, are among the symptoms, eye tests will be done to understand the exact nature of those problems.

Additional tests may include:

• A neurological exam to check mental status, coordination, reflexes and muscle function
• Blood and urine tests to check hormone levels; the blood tests, or venous sampling, involve taking blood from peripheral veins in the arms to look at hormone levels originating from the pituitary gland in the brain
• Magnetic resonance imaging (MRI) or computerized tomography (CT) scan to get visual images of the pituitary and pineal glands, the optic nerves, brain and spinal cord
• Lumbar puncture, a procedure to draw a sample of cerebrospinal fluid, which is then tested for signs of tumor

If tests and images indicate the likelihood of a CNS germ cell tumor, a biopsy may be done to surgically remove a sample of the tumor for examination under a microscope. The surgeon may remove the tumor, or the portion that can be safely removed, as part of the same procedure.

Treatment for germ cell tumors

The goal of treatment for CNS germ cell tumors is to eliminate or shrink the tumor to minimize the risk of cancerous growth and to relieve symptoms.

• Radiation therapy may be used to kill tumor cells or shrink the tumor. CNS germ cell tumors are highly sensitive to radiation, and in many cases, this is the only treatment needed. Proton beam therapy (PBT) has been found to be effective in treating cancerous tumors in the head and neck with fewer side effects than traditional radiation treatment.
• Chemotherapy may be paired with radiation therapy for certain types of germ cell tumors.
• Surgery may be done in rare cases to remove all or most of the tumor.

Follow-up care

Lifelong follow-up is generally needed.

• Follow-up tests and imaging will be needed periodically to make sure the tumor has not returned.
• Medication to replace hormone production may be needed if the function of the pituitary or pineal glands has been damaged by the tumor.

Why choose CHOP?

Children with germinoma often require care from many pediatric specialties.

Our Neuro-Oncology Program is internationally recognized for having the highest quality neurosurgery, neuro-imaging and neuro-pathology support. They are the primary specialty team who help coordinate care for children with CNS germ cell tumors.

Our highly skilled Neurosurgery Program also offers a full range of inpatient and outpatient services to infants, children and adolescents, and have treated patients from all over the world with this type of condition. 

Additionally, the Neuroendocrine Center at Children’s Hospital of Philadelphia (CHOP) offers families a coordinated and multidisciplinary approach to treatment for neuroendocrine disorders. Our team will help combine the expertise of pediatric endocrinologists, neuro-oncologists, neuro-surgeons, neuro-ophthalmologists, neuro-radiologists and pathologists.

All of our team members have vast experience in the treatment of complex neuroendocrine conditions.