A Schwannoma is a tumor of the peripheral nervous system or nerve root. A Schwannoma develops from cells called Schwann cells, a type of cell that wraps itself around peripheral nerves and provides protection and support. Schwannomas are almost always benign (not cancerous), but rarely, may become cancerous (a malignant Schwannoma). Symptoms of a Schwannoma may be vague and will vary depending on its location and size, but may include a lump or bump that can be seen or felt, pain, muscle weakness, tingling, numbness, hearing problems, and/or facial paralysis. Sometimes Schwannomas do not cause any symptoms. Schwannomas usually develop in otherwise healthy people for unknown reasons. In some cases, a Schwannoma is caused by a genetic disorder such as neurofibromatosis 2 (NF2), Schwannomatosis, or Carney complex. People with these genetic disorders usually have more than one Schwannoma. Schwannomas may be diagnosed using imaging studies. A biopsy may confirm the diagnosis.