Nerve Tumors

What is a nerve tumor?

Nerve tumors can form in the peripheral nerve network anywhere in the body. These tumors often affect the function of the nerve, causing pain and disability. A large majority of peripheral nerve tumors are benign (not cancerous). Some are caused by neurofibromatosis, or schwannomatosis (genetic disorders of the nervous system).

There are three major categories of nerve tumors. They are:

1. Neurofibroma. Most commonly found within the genetic disorder of neurofibromatosis.
2. Schwannoma. These are nerve sheath tumors and can occur in isolation. Less commonly these tumors can occur in patients suffering from neurofibromatosis or schwannomatosis.
3. Malignant Peripheral Nerve Sheath Tumor. These very aggressive tumors are cancerous nerve sheath tumors and should be managed by a multi-disciplinary team. They can occur in association with neurofibromatosis Type 1.

Types of nerve tumors

Schwannomas

Schwannomas are tumors that grow along the peripheral nervous system in the body. A common cause of schwannomas is schwannomatosis.

For many patients, the tumors are watched over time, as they can grow very slowly. These tumors need to be removed when patients feel pain or the tumors are observed to be growing quickly.

Neurofibromas

Neurofibromas are benign (non-cancerous) tumors which grow on nerves in the body. A common cause of neurofibromas is neurofibromatosis.

Patients with neurofibromatosis often have numerous tumors throughout their body. If a tumor begins to cause pain or is associated with loss of neurological function, compresses a nearby structure, or shows rapid growth on imaging, surgical excision (removal) may be considered.  If there is a question of the tumor being malignant (cancerous), sophisticated imaging using a PET/CT scan and image-guided stereotactic biopsy can resolve if the tumor is cancerous.

Malignant Nerve Sheath Tumors

Also called neurofibrosarcoma, nerve sheath tumors are malignant (cancerous) tumors that grow in the cells surrounding peripheral nerves. A common cause of nerve sheath tumors is neurofibromatosis type 1 (NF1).

These tumors should be removed to prevent local recurrence of malignancy and to halt growth and possible spreading of the cancer (metastasis) throughout the body. These are aggressive tumors that may require aggressive medical therapy (chemotherapy) or radiation therapy in addition to surgery.

Symptoms of a nerve tumor

The symptoms caused by these tumors can vary. Some patients are asymptomatic, meaning they have no symptoms. Possible symptoms may include:

• Pain
• A mass, or thickening in the muscle fibers
• Numbness, burning, or “pins and needles”
• Weakness in the affected muscles
• Dizziness/loss of balance

Diagnosis of a nerve tumor

Your doctor will examine you carefully and may order several imaging studies including:

• MRI Neurography
• CT
• EMG (electrodiagnostic study to examine electrical pathways in the nerves)

Treatment options for nerve tumors

Nonsurgical treatment options

For many patients non-operative care is the most appropriate treatment. The tumors are often slow growing and can remain asymptomatic for a long period of time. Following patients with serial examinations and imaging studies can provide a guide to if, and or when, a patient may require surgery. 

Surgical treatment options

There are several factors in deciding to surgically remove these tumors. Some, like schwannomas are slow-growing and can be watched using imaging studies over time. Others, like malignant nerve sheath tumors need to be removed immediately, as they are very aggressive.

Dr Allan Belzberg is a world-renowned neurosurgeon in the treatment of peripheral nerve injuries. He treats on average 500 nerve injuries every year and has published research publications focusing on improving surgical repairs of nerve injuries and discovering new treatment options. Catch up on the latest research on nerve injuries.

To make an appointment or request a consultation, contact the Johns Hopkins Peripheral Nerve Surgery Center at 410-614-9923.