Peripheral nerve tumors

Although they’re rare, there are many types of peripheral nerve tumors. Our specialists will help you gather information about your condition and choose the treatments you need.

What is a peripheral nerve tumor?

Peripheral nerve tumors are usually benign tumors that grow on the peripheral nerves – the nerves that branch out from the brain and spine (central nervous system). They can occur anywhere there is a nerve. Some peripheral nerve tumors are cancerous or have the potential to grow and become cancerous.

Benign tumors are usually small and slow-growing. If benign tumors grow too big or are associated with important functions like breathing, they can still cause problems. When they get too big, they may put pressure on nearby tissues and cause pain, damage to the nerves or nearby tissues or loss of functions associated with those nerves and tissues.

Peripheral nerve tumor types

The naming and categorizing of peripheral nerve tumors varies. Some types of tumors have more than one name associated with them. Some are so rare that not much is known about them.

The most common types of peripheral nerve tumors in adults are schwannomas. They’re usually benign and can occur anywhere in the body. They grow from Schwann cells, which form the myelin – a protective layer on the outside of nerves.

Vestibular schwannomas, which grow in the inner ear, are sometimes associated with brain tumors because the nerves they grow on are inside the skull and close to the brain.

Some peripheral nerve tumors called neurofibromas are associated with neurofibromatosis type 1 or neurofibromatosis type 2. Neurofibromatosis type 1 and 2 (NF1 and NF2) are conditions that cause tumors and other growths. Sometimes these conditions are inherited and sometimes they occur spontaneously. Most neurofibromas are benign.

Malignant peripheral nerve sheath tumors

A small percentage of neurofibromas and schwannomas can become malignant peripheral nerve sheath tumors (MPNSTs). These tumors are fast-growing and often grow on nerves in the legs, arms or pelvis. They can be resistant to chemotherapy treatment and often recur after treatment.

Symptoms and signs of peripheral nerve tumors

Different peripheral nerve tumors have signs and symptoms that depend on the type of tumor and its size, location, and how fast it grows.

Small, slow-growing tumors may have mild symptoms or even no symptoms.

Signs and symptoms also vary depending on the person. However, some signs and symptoms that occur with many tumors include:

• Fatigue
• Loss of movement
• Pain, numbness or tingling in the affected body part
• Visible lump or deformed appearance
• Weakness

Diagnosis of peripheral nerve tumors

Your doctor will perform a physical exam and gather your family medical history. They’ll want to know about the duration and intensity of your potential peripheral nerve tumor symptoms. They’ll order imaging tests such as MRI, CT, PET or ultrasound based on which ones will provide better information about your potential tumor and surrounding tissues.

Your doctor is likely to recommend a surgical biopsy to confirm the diagnosis. A pathologist will examine the biopsy and provide information about the appearance of the cells to help identify the type of tumor.

Treatment for peripheral nerve tumors

Treatment depends on the location, size, type and growth rate of the tumor.

For some benign tumors that are small, slow-growing and not likely to cause significant symptoms, we’ll recommend ongoing observation. We’ll schedule you for regular checkups and imaging scans to make sure it’s still growing slowly.

Surgery on peripheral nerve tumors carries risks unique to the type of tumors. For example, surgery on a vestibular schwannoma needs to be done in an area that’s hard to access and may be close to the brain stem.

Any surgery on a peripheral nerve tumor requires your surgeon to be careful to avoid any damage to the nerve or surrounding tissues. It may be difficult to remove the entire tumor because of its size or location.

Surgery may be recommended for some benign tumors that are associated with important functions or may affect nearby organs or tissues. In these cases, we’ll recommend surgery to remove as much of the tumor as possible.

Malignant peripheral nerve sheath tumor treatment usually includes cancer surgery to remove as much of the tumor as possible. In extreme cases, surgery for an MPNST may require partial amputation of an affected limb.

Radiation therapy and chemotherapy may be used before surgery to shrink the tumor, after surgery to remove the rest of the tumor, or both before and after surgery.