Peripheral nerves branch off the central nervous system to control functions throughout the body. Tumors, which include neurofibromas and schwannomas, may form on or near peripheral nerves, affecting function. The vast majority of peripheral nerve tumors are benign, and their cause is unknown.
However, a peripheral nerve tumor can damage the nerve and lead to loss of muscle control. The most common sites include the sciatic nerve (running from the lower back, through the buttock and into the leg), brachial plexus (in the neck), and sacral plexus (above the sciatic nerve). Symptoms include pain, numbness, and/or weakness.
These tumors can usually be removed safely.