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What is schwannoma?

Schwannoma is a rare type of tumor that forms in the nervous system. Schwannoma grows from cells called Schwann cells. Schwann cells protect and support the nerve cells of the nervous system. Schwannoma tumors are often benign, which means they are not cancer. But, in rare cases, they can become cancer. 

How common is schwannoma?

Schwannoma is not common. It is a rare disease, which means it affects fewer than 200,000 people. Schwannoma is the most common type of peripheral nerve tumors in adults. Schwannoma can occur in people of all ages.

How is schwannoma diagnosed?

Some people with schwannoma have symptoms, but others don’t. Symptoms may differ depending on where the tumor is in the body. Symptoms can include:

  • Hearing loss or ringing in the ears
  • Dizziness and balance problems
  • Pain
  • Facial paralysis
  • Trouble swallowing 
  • Trouble moving the eye
  • Numbness or tingling
  • Muscle weakness

Imaging: If you have symptoms of schwannoma, your doctor will use scans such as CT and MRI to see where the tumor is in the body and how big it is. They will also check for signs that the tumor has spread to other parts of the body, which can happen in rare cases.

Biopsy: To check if the tumor is schwannoma, your doctor may do a biopsy, taking a small sample from the tumor with a needle. An expert, called a pathologist, will study cells from the sample under the microscope and run other tests to see what kind of tumor it is.

How is schwannoma treated?

Treatment for schwannoma depends on where the tumor is in the body and how quickly it is growing. 

Watch and wait:  If the tumor is growing very slowly, it may be safest for your doctor to check it often without treating it. 

Surgery: If the tumor is growing more quickly or causing other problems, doctors may remove it with surgery. 

Radiation Therapy: Radiation therapy may be used with surgery. The radiation is aimed at the area where the tumor was removed to prevent it from growing back.

Does schwannoma run in families?

Schwannoma rarely runs in families. There are some genetic conditions which may run in families that may increase the risk of schwannoma, such as neurofibromatosis type 2 (NF2), schwannomatosis, and Carney Complex.  

How does schwannoma form?

Schwannoma forms when Schwann cells, a type of cell that protects nerve cells in the nervous system, grows and divides more than normal. Scientists are always working to understand how tumors form, but it can be hard to prove. 

What is the prognosis for someone with schwannoma?

The estimate of how a disease will affect you long-term is called prognosis. Each person is different and prognosis will depend on many factors, such as

  • Where the tumor is in your body
  • If the cancer has spread to other parts of your body
  • How much of the tumor was taken out during surgery

If you want information on your prognosis, it is important to talk to your doctor. NCI also has resources to help you understand cancer prognosis.

The prognosis for a person with schwannoma depends on the size of the tumor and whether it has spread to other parts of the body. Depending on where the tumor is, people may have long term muscle weakness or hearing loss. If the entire tumor is removed by surgery, it is not likely to grow back.