Embryonal tumors


Embryonal tumors are uncontrolled growths of cells in the brain. The growths involve cells that are left over from fetal development, called embryonal cells.

Embryonal tumors are a type of brain cancer, also called malignant brain tumor. This means the cells that make up the tumor can grow to invade the brain and cause damage to healthy brain tissue. They also can spread through the fluid that surrounds the brain and spinal cord, called cerebrospinal fluid.

Embryonal tumors most often happen in babies and young children. But they can happen at any age.

There are several kinds of embryonal tumors. The most common is medulloblastoma. This type of embryonal tumor starts in the lower back part of the brain, called the cerebellum.

Symptoms of embryonal tumors vary, depending on the type of tumor, location, size and other factors, such as whether pressure builds up within the brain. Symptoms may include:

  • Headaches.
  • Nausea.
  • Vomiting.
  • Unusual tiredness.
  • Dizziness.
  • Double vision.
  • Unsteady walk.
  • Seizures.
  • Other issues.

If your child is diagnosed with an embryonal tumor, seek care at a medical center that has experience caring for children with brain tumors. Medical centers with expertise in pediatric brain tumors provide access to the latest treatments and technology to ensure proper diagnosis and treatment.


Your health care team reviews your child's medical history and symptoms. Tests and procedures used to diagnose embryonal tumors include:

  • Neurological exam. During this procedure, vision, hearing, balance, strength, coordination and reflexes are tested. This helps find out which part of the brain might be affected by the tumor.
  • Imaging tests. Imaging tests make pictures of the brain. The pictures can show the size and location of the tumor. The pictures may show pressure or blockages of the fluid in the brain. CT and MRI are often used to diagnose brain tumors. Advanced techniques, such as perfusion MRI and magnetic resonance spectroscopy, also may be used.
  • Removal of tissue for testing. A biopsy is a procedure to remove a sample of tissue from the tumor for testing. The sample is often taken during surgery to remove the tumor. Your child's health care team may want to remove tissue before surgery if the imaging tests show features that aren't typical of embryonal tumors. The tissue is looked at in a lab to determine the types of cells.
  • Removal of cerebrospinal fluid for testing. A spinal tap, also called a lumbar puncture, involves inserting a needle between two bones in the lower spine. The needle draws out the fluid from around the spinal cord. The fluid, called cerebrospinal fluid, is tested to look for tumor cells or other things that aren't typical. This test is only done after managing the pressure in the brain or removing the tumor.


Treatment for embryonal tumors usually involves surgery. Other treatments might be used after surgery to reduce the risk that the tumor may come back. Which treatments are best for your child depends on your child's age. Your child's health care team also considers the type of embryonal tumor and its location.

Embryonal tumor treatment options may include:

  • Surgery to relieve fluid buildup in the brain. Some embryonal tumors may block the flow of fluid in the brain. This can cause a buildup of fluid that puts pressure on the brain, called hydrocephalus. To reduce the pressure, a brain surgeon, also called a neurosurgeon, can create a pathway for the fluid to flow out of the brain. Sometimes this procedure can be combined with surgery to remove the tumor.
  • Surgery to remove the tumor. A brain surgeon removes as much of the tumor as possible. The surgeon takes care not to harm nearby tissue. Typically, children with embryonal tumors receive additional treatments after surgery to target any remaining cancer cells.
  • Radiation therapy. Radiation therapy uses powerful energy beams to kill tumor cells. The energy can come from X-rays, protons and other sources. During radiation therapy, a machine directs beams of energy to specific points on the body. Standard radiation uses X-rays. A newer form of radiation uses proton beams. Proton beam radiation can be carefully targeted to deliver the radiation to the area of the tumor or other areas at risk. This lowers the risk of hurting nearby healthy tissue. Proton beam therapy is available at a limited number of health care centers in the United States.
  • Chemotherapy. Chemotherapy uses strong medicines to kill tumor cells. Many chemotherapy medicines are given through a vein, but some are taken in pill form. Chemotherapy may be recommended after surgery or radiation therapy. Sometimes it's done at the same time as radiation therapy.
  • Clinical trials. Clinical trials are studies of new treatments. These studies give your child a chance to try the latest treatment options. The risk of side effects for these treatments may not be known. Ask a member of the health care team whether your child can participate in a clinical trial.

Content From Mayo Clinic Updated: 04/11/2023
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