neurofibromatosis
n. an autosomal dominant neurological disorder that is characterized by tumors of the peripheral nervous system (neurofibromas). The tumors may be firm subcutaneous nodules or soft cutaneous lumps that form a pocket when pressed. Three subtypes have been identified: Type 1 (also called von Recklinghausen’s disease) is present at birth with pigmented (pale brown) patches on the skin and deformed bones; Type 2 begins in adolescence with ringing in the ears, poor balance, and eventual hearing loss; and schwannomatosis, the rarest form, causes intense, chronic pain and other neurological symptoms such as tingling, numbness, and weakness in the fingers and toes. Neurofibromatosis can be either an inherited disorder or the product of a gene mutation.