Embryonal Tumors

What are embryonal tumors?

An embryonal tumor is a type of brain tumor made up of fast-growing cells that are left over after fetal development (embryonic cells). 

Embryonic cells have an important function during the early stages of fetal development in the uterus. They help form a human body. Sometimes, extra embryonic cells remain in your child’s brain after birth. This leads to the formation of embryonal tumors.

These tumors affect children and can be cancerous (malignant) or noncancerous (benign). Most develop in the brain and some form along the spinal cord. These tumors can spread through fluid that surrounds the brain and spinal cord (cerebrospinal fluid). Many malignant types are aggressive and can be life-threatening.

You may hear your child’s healthcare provider refer to embryonal tumors as embryomas. In the past, providers called this type of tumor a primitive neuroectodermal tumor (PNET).

What are the types of embryonal tumors?

Embryonal tumors are grouped into different tumor types. The most common type of embryonal tumor is a medulloblastoma. It develops in the cerebellum, which is the lower back part of your child’s brain.

Other non-medulloblastoma embryonal tumors of the central nervous system include:

• Atypical teratoid/rhabdoid tumor (AT/RT): It develops in the cerebellum (back of the brain).
• Embryonal tumor with multilayered rosettes (ETMRs) either C19MC-altered or NOS (not otherwise specified): It develops in the cerebrum or the front and top of the largest part of the brain and in the spinal cord.
• Medulloepithelioma: It forms in the brain, spinal cord and nerves outside of the spinal column. These aggressive, fast-growing tumors occur most often in very young children, with a poor prognosis.
• Central nervous system neuroblastoma: It forms in the layers of tissue that cover the brain and spinal cord and in cerebrum nerve tissue.
• Cribriform neuroepithelial tumor: It forms in the fluid-filled cavities (ventricles) of the brain.

How common are embryonal tumors?

Embryonal tumors make up an estimated 12% of all brain tumors in children from birth to age 14 in the United States. Among these, the most common, medulloblastoma, accounts for over 68% of all embryonal tumors. Atypical teratoid/rhabdoid tumors account for 17%.

These tumors are most common among babies and children. They can affect adults but it’s rare. For example, atypical teratoid/rhabdoid tumors affect more children assigned male at birth younger than 3 years old. Embryonal tumors with multilayered rosettes are more common among children assigned female at birth younger than 4 years old.

What are the signs and symptoms of embryonal tumors?

The signs and symptoms of embryonal tumors vary based on your child’s age, the type and the location but could include:

• Headache, usually in the morning.
• Nausea and vomiting.
• Fatigue or lethargy.
• Vision problems.
• Seizures.

Among infants, you might notice the following symptoms:

• Larger head size.
• Behavioral changes (like irritability).
• Difficulty with balance and coordination.
• Poor feeding.
• Missing developmental milestones for their age. 

What causes embryonal tumors?

A tumor happens when cells grow and divide more often than they should. Researchers aren’t sure why leftover embryonic cells turn into embryonal tumors.

What are the risk factors for embryonal tumors?

The following inherited conditions make your child more likely to develop a medulloblastoma embryonal tumor:

• Turcot syndrome.
• Rubinstein-Taybi syndrome.
• Gorlin syndrome.
• Li-Fraumeni syndrome.
• Fanconi anemia.

What are the complications of embryonal tumors?

Complications of embryonal tumors can be life-threatening and may include:

• Fluid buildup and pressure on the brain (hydrocephalus).
• Brain damage.
• Cognitive impairment.
• Changes to how hormones function (endocrinopathies).

How are embryonal tumors diagnosed?

If your child shows symptoms or you have concerns about their health, visit your child’s healthcare provider. A provider will diagnose an embryonal tumor after a physical exam and testing. Your child’s provider will ask you questions to learn more about their symptoms. They’ll also ask about your child’s health history and family medical history. 

Tests that confirm a diagnosis include:

• An MRI.
• A CT scan.
• A lumbar puncture.
• A biopsy.

How are embryonal tumors treated?

Treatment for embryonal tumors varies based on the type, size and location of the tumor. Common treatment options may include:

• Removal surgery.
• Radiation therapy.
• Chemotherapy.
• Targeted therapy (medications).

Your child may need more than one type of treatment. For example, your child’s surgeon will remove as much of the tumor as they safely can during a procedure. Following this, your child will undergo chemotherapy to reduce or eliminate the remaining tumor.

Research is ongoing to learn more about embryonal tumors. Your child may be a candidate for clinical trials (tests on people) to help healthcare providers discover new treatment options.

During your child’s treatment, you may feel stressed and overwhelmed. Many parents and caregivers participate in support groups or speak with a mental health professional during this difficult time. In addition, your child’s healthcare providers can show you ways to support and comfort your child as they undergo treatment.

Are there side effects of the treatment?

Side effects of surgery may include:

• Bleeding.
• Blood clot.
• Infection.
• Nerve damage.

Side effects of radiation and chemotherapy may include but aren’t limited to the following:

• Fatigue.
• Nausea and vomiting.
• Hair loss.
• Skin irritation.
• Headaches.

Some tumors can return after treatment to remove them.

What is the prognosis for embryonal tumors?

Your child’s prognosis varies depending on the following:

• Tumor type.
• Tumor location.
• Whether or not the cancer spreads.
• Age.
• Results of surgery or previous treatment.
• General health.

Some embryonal tumors are aggressive, spread easily and can return after treatment. Others may be benign (noncancerous). Your child’s healthcare provider will be able to give you the most accurate prognosis.

What is the life expectancy for embryonal tumors?

The life expectancy for children with this condition varies. For example, one study reported that around 33% of children diagnosed with medulloblastoma don’t survive due to complications. The survival rate for an aggressive embryonal tumor with multilayered rosettes is 12 months after a diagnosis.

Your child’s life expectancy may differ from others with the same type of tumor based on the tumor size and location. Your child’s healthcare providers will give you the most up-to-date information about treatment options and available care to increase your child’s chance of survival.

When should I see a healthcare provider?

Visit your child’s healthcare provider if you notice symptoms of embryonal tumors like:

• Missed developmental milestones.
• Behavior changes.
• Difficulty feeding.
• Trouble with balance and walking.
• Frequent nausea and vomiting.

If your child has a seizure, contact 911 (or your local emergency services number) or visit the emergency room immediately.

What questions should I ask my healthcare provider?

• Where is the tumor located?
• What type of treatment do you recommend?
• What are the side effects of treatment?
• How do I support my child through treatment?
• What’s my child’s prognosis?