A schwannoma is the abnormal growth of Schwann cells, which line and insulate nerves. It is usually benign and rarely spreads to affect other tissues and organs, but malignant schwannomas that spread are called neurofibrosarcomas or malignant peripheral nerve sheath tumors (MPNSTs). The cancer can occur anywhere in the body but the most common areas include:
- 8th cranial nerve (controls hearing)
- sacral plexus (network of nerves in the lower back)
- brachial plexus (network of nerves controlling the arm)
- sciatic nerve (nerve of the leg)
Schwannomas affect the organ or region that the nerve supplies. Symptoms include swelling on the face with or without pain, ringing in the ears or hearing loss, loss of balance and coordination, and pain, soreness or formation of a lump in the arms or legs. Schwannomas can be diagnosed with the help of physical and neurological examinations, imaging tests (CT scan and MRI) and biopsy (microscopic examination of the tumor tissue sample). Treatment most frequently requires the removal of the tumor through surgery. Radiation therapy (high intensity radiation) and chemotherapy (medication) may also be performed individually or in combination to kill the cancerous Schwann cells and stop them from recurring.