Nerve Tumors

Nerve tumors can form in the peripheral nerves; the extensive network of nerves running throughout the body. These tumors affect the function of the nerve, causing pain and disability.

Nerve tumors may occur anywhere in the body. A large majority of peripheral nerve tumors are benign (not cancerous). Some are caused by neurofibromatosis or schwannomatosis (genetic disorders of the nervous system).

The trusted experience and surgical expertise of the neurosurgeons at The Johns Hopkins Peripheral Nerve Surgery Center make us the best choice for treatment of this condition.

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

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

Symptoms
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 area
• Dizziness/loss of balance

Causes
It is not known what causes these tumors. Patients who have neurofibromatosis type 1 (NF1) have an increased risk of developing these kinds of tumors. Fifty percent of these kinds of tumors are found in people with NF1.

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

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

Surgical Intervention
Nerve sheath tumor surgery is designed to remove the tumor as completely as possible. In the case of schwanommas, the nerve can usually be left intact as the tumor is peeled off the surface of the nerve using microsurgical technique. In the case of a neurofibroma, the tumor is inside the nerve and the nerve must be opened and the tumor is taken from within. In most cases, these tumors can be removed and the nerves preserved. In the rare cases where keeping the nerve intact is impossible, nerve repair is performed at the same time as the tumor removal surgery.

Factors in Surgical Intervention
There are several factors in deciding to surgically remove these tumors. Some, like schwanommas 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.
Schwanommas: 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: If this tumor begins to cause pain, or loss of neurological function, compressing a nearby structure or shows rapid growth on imaging, the tumor should be removed immediately. If there’s a question of malignancy in the case of this kind of tumor, sophisticated imaging using a PET/CT scan and image guided stereotactic biopsy can resolve if the tumor is cancerous.
Malignant Nerve Sheath Tumors: These tumors should be removed to prevent local recurrence of malignancy and to halt growth and possible spreading of the cancer throughout the body. These are aggressive tumors that require aggressive therapy.

Recovery
Recovery depends on the type of tumor, location and extent of the surgery. Your doctor will give you detailed instructions about surgery and recovery. If your tumors are malignant, your doctor will work with our oncology team to try and insure maximum function of the nerves when cancer treatment is finished.