Neurofibromas are tumors of the nerve fibers. The term neurofibromatosis refers to two different genetic diseases characterized by skin abnormalities and nervous system tumors:
Tumor location depends on the type of neurofibromatosis present.
NF-1 can cause neurofibromas to appear throughout the body. These tumors often are visible underneath the skin. It can also cause skin discolorations called “café-au-lait” spots, as well as freckles in the armpits and groin.
Other nervous system tumors can be associated with NF-1; these occur in approximately 10% of patients and include optic pathway gliomas (usually pilocytic astrocytoma), cerebral hemisphere, posterior fossa (brain stem and cerebellum), and low-grade astrocytomas in the spinal cord.
NF-2 Nervous system tumors associated with this type may include tumors of the hearing nerve (acoustic neuromas or vestibular Schwannoma), typically on both sides, meningiomas, schwannomas or the spinal root of nerves, and ependymomas (spinal cord or brain).
The symptoms of NF-1 and NF-2 present themselves in very different ways. One of the most common early signs of NF-1 are the skin discolorations referred to as “café-au-lait” spots. Because NF-2 tumors may involve the hearing nerve, unexplained hearing loss or ringing in the ears might be an early symptom.
Surgery is the most common form of treatment for neurofibroma. However, removal of the tumor can be tricky because these growths are often woven through the nerve structure.
NF-1 is the more common form of neurofibroma, appearing in one of every 3000 or 4000 people worldwide. NF-2 is a little more rare, occurring in one of every 35,000-40,000.