Schwannomas are tumors of the tissue that cover the nerves (nerve sheath). These tumors develop from a type of cell called a Schwann cell, which gives them their name. They are usually not cancerous (benign). Although schwannomas can develop from any nerve in the body, the most common areas include the nerves of the head and neck and those involved with flexing in the arms and legs. Some of the common symptoms include a slow-growing mass and an electric-like shock when the affected area is touched (Tinel shock). Some people may experience numbness or other neurological symptoms depending on the size and location of the tumor.

Cause of schwannomas is unknown, but they sometimes occur in people with certain disorders including some types of neurofibromatosis (genetic disorders that disturb cell growth in the nervous system, causing tumors to form on nerve tissues). Benign schwannomas are typically treated with surgery.

How is it diagnosed?

In addition to a complete physical exam and medical history review, the following tests may be necessary to diagnose a schwannoma: X-ray, ultrasound and/or magnetic resonance imaging (MRI). Some people may also need a biopsy of the tumor to confirm the diagnosis.

Genetic testing is not available for many individuals with schwannomas since most of these tumors occur sporadically (by chance) and are not caused by a genetic mutation. However, genetic testing is an option for people with an inherited condition that predisposes to schwannomas such as certain types of neurofibromatosis (neurofibromatosis type 2 and schwannomatosis). Carrier testing for at-risk relatives and prenatal testing are possible if the disease-causing mutation in the family is known. If you have specific questions about a genetic test, you should contact your health-care provider or genetics professional.

What are the treatment options?

The best treatment options for schwannoma depend on several factors, including the size and location of the tumor; whether the tumor is benign or malignant (cancerous); and the age and overall health of the affected person. Standard treatment for benign schwannomas is to surgically remove as much of the tumor as possible. People with malignant schwannomas may also be treated with radiation therapy and/or chemotherapy in addition to surgery.