Neurofibromatosis

What is it?

Neurofibromatosis is a condition in which nerve tumors grow throughout the body. Three types of neurofibromatosis have been identified: neurofibromatosis I (NF1), neurofibromatosis II (NF2), and schwannomatosis. Each type of neurofibromatosis is caused by a mutation in a specific gene.

Symptoms

Symptoms of NF1 include spots on the skin, freckles under the arms or in the groin, changes in the bones, and the formation of nerve tumors called neurofibromas. Neurofibromas are usually benign tumors. Only about 5% of NF1 patients develop spinal tumors that cause them symptoms. Many more have spinal tumors that do not cause symptoms.

Symptoms of NF2 include tinnitus (ringing or buzzing in the ears), hearing loss, balance problems, and benign tumors (meningiomas, ependymomas, and schwannomas). People with NF2 are much more likely than those with NF1 to develop symptomatic spinal tumors.

Most tumors associated with neurofibromatosis are benign. But even benign tumors can cause problems when they compress the spinal nerve roots or spinal cord. Symptoms of nerve root and cord compression include pain, changes in sensation (numbness, tingling), changes in movement (clumsiness, weakness), or difficulty controlling bowel or bladder.

Diagnosis

Neurofibromas, schwannomas, and meningiomas can be identified on MRI (magnetic resonance) and CT (computed tomography) scans.

Treatment

The treatment of the tumors caused by neurofibromatosis depends on the size, location, and symptoms of the tumors. Small tumors in patients with no symptoms usually are just regularly observed. For larger or symptomatic tumors, or tumors showing growth over time, surgical removal is usually recommended. In most patients, complete removal of these tumors can be safely achieved using a surgical microscope, very fine instruments, and an array of microsurgical techniques.