Schwannoma in the leg
Benign tumors can occur in nerves, muscle and bone. This illustration shows a schwannoma of the tibial nerve in the leg.
A more complex nerve sheath tumor may assume the shape of a dumbbell. These occur in the spine and pelvis and are intertwined with important nerves.
Acoustic neuroma (vestibular schwannoma)
An acoustic neuroma (vestibular schwannoma) is a benign tumor that develops on the balance and hearing nerves leading from your inner ear to the brain. These nerves are twined together to form the vestibulocochlear nerve (eighth cranial nerve). The pressure on the nerve from the tumor may cause hearing loss and imbalance.
Peripheral nerve tumors are growths in or near the strands of tissue (nerves) that transmit signals from your brain to the rest of your body. These nerves control your muscles so that you can walk, blink, swallow, pick things up and do other activities.
Peripheral nerve tumors can occur anywhere in the body. Most of them aren't cancerous (malignant), but they can lead to pain, nerve damage and loss of function in the affected area.
Treatment of peripheral nerve tumors usually involves surgery to remove the tumor. Sometimes the tumor can't be removed without damaging nearby healthy tissue and nerves. In these cases, other treatments may be recommended.
Several types of peripheral nerve tumors occur. These tumors affect nerves by growing within them (intraneural tumors) or by pressing against them (extraneural tumors).
The symptoms and signs 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 signs and symptoms, although tumor size doesn't always determine effects.
Signs and symptoms of peripheral nerve tumors vary depending on the location of the tumors and which tissues are affected. They include:
- Swelling or a lump under your skin
- Pain, tingling or numbness
- Weakness or loss of function in the affected area
- Dizziness or loss of balance
When to see a doctor
See your doctor when you have any of the symptoms listed, especially if you have a lump that grows rapidly.
The spinal cord is housed within a hollow chamber within the vertebrae (spinal canal). It extends from the base of the skull to the lower back.
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 a malfunctioning gene or triggered by injury or surgery.
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. These tumors, which are frequently multiple, can lead to a variety of symptoms and signs depending on their location. These tumors are usually noncancerous.
- A history of radiation treatment. If you were exposed to radiation, you are at increased risk of peripheral nerve tumors years later.
Both noncancerous and cancerous peripheral nerve tumors can compress nerves, leading to complications, some of which may be permanent:
- Numbness and weakness in the affected area
- Loss of function in the affected area
- Difficulties with balance
Peripheral nerve tumors care at Mayo Clinic
May 17, 2019
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