Overview

Peripheral nerve tumors are growths that form in or near nerves. Nerves are strands of tissue that transmit signals from the brain to the rest of the body. Peripheral nerves control muscles that allow you to walk, blink, swallow, pick things up and do other activities.

Peripheral nerve tumors can occur anywhere in the body. Most of them are benign, meaning they're not cancerous. But they can lead to pain, nerve damage and loss of function in the affected area.

Treatment usually involves surgery to remove the tumor. When the tumor can't be removed without damaging nearby healthy tissue and nerves, other treatments may be considered.

There are several types of peripheral nerve tumors. Intraneural tumors grow within nerves. Extraneural tumors press against nerves.

Symptoms

The symptoms of a peripheral nerve tumor develop from direct effects on the main nerve or from the tumor pressing on nearby nerves, blood vessels or tissues. As the tumor grows, it may be more likely to cause symptoms, although tumor size doesn't always determine effects.

Symptoms of peripheral nerve tumors vary depending on where the tumors are located and the tissues affected. They include:

  • Swelling or a lump under the skin.
  • Pain, tingling or numbness.
  • Weakness or a loss of function in the affected area.
  • Dizziness or a loss of balance.

When to see a doctor

See your health care provider if you have any of the symptoms listed, especially if you have a lump that grows quickly.

Causes

It's not clear why most peripheral nerve tumors develop. Some are linked to known inherited syndromes, such as neurofibromatosis (types 1 and 2) and schwannomatosis. Others may be caused by changes in a gene.

Risk factors

Peripheral nerve tumors are more common in people who have:

  • Neurofibromatosis (types 1 and 2) and schwannomatosis. In these disorders, tumors develop on or near the nerves throughout the body. There are often multiple tumors. They can lead to a variety of symptoms depending on where they are in the body. These tumors are usually not cancerous.
  • A history of radiation treatment. A person who was exposed to radiation is at higher risk of developing peripheral nerve tumors years later.

Complications

Peripheral nerve tumors can press against nerves. This can lead to complications. Some may be permanent:

  • Numbness and weakness in the affected area.
  • Loss of function in the affected area.
  • Trouble with balance.
  • Pain.
By Mayo Clinic Staff