Neurofibromatosis, type II (NF2) is a hamartoneoplastic syndrome, characterized by the presence of benign tumors in the nervous system, particularly vestibular Schwannomas or acoustic neuromas. Acoustic neuromas grow along the auditory nerve, causing bilateral acoustic neurinomas, which is a characteristic feature of the condition. Apart from these growths, tumors may also grow on other areas of the nervous system, including the brain and the spinal cord. Although the genetic defect underlying this condition is present at birth, symptoms usually appear only by the second or third decade of life. These include hearing loss accompanied with ringing and noises in the ears, difficulty in maintaining balance, and headaches. Other symptoms vary according to the site of tumor growth. Tumors affecting the ocular nerves cause changes in vision, and cataracts, often beginning as early as in childhood. Other symptoms include coffee colored marks on the skin, facial weakness, limb weakness, swellings under the skin, and fluid accumulation in the brain. The condition shows variable expressivity, ranging from the Gardner type, a mild form that persists through life, to a severe condition known as Wishart type, which presents with more than three tumors at a young age. It is estimated that 1 in 40,000 individuals are affected by NF2.
Individuals with bilateral acoustic neurinomas and a family history of NF2, neurofibroma, meningioma, glioma, Schwannoma, or juvenile posterior subcapsular cataract are highly likely to be affected with NF2. Genetic testing is available to confirm the diagnosis. In individuals with a family history of the condition, genetic testing can detect affected patients at an early stage, thereby facilitating management of the disease. Surgery to physically remove the tumors is the only reliable method for therapy. Radiosurgery is also being considered as an alternative to conventional surgery, although there are chances of malignant changes occurring to the nearby tissues as a result of irradiation. Hearing loss is usually managed, either by a cochlear implant, or in cases of cochlear damage, by an auditory brainstem implant. Although the tumors themselves are benign, their location in the nervous system makes them more serious. Prognosis for the milder forms of the disease is generally good. However, patients affected with the Wishart form usually do no survive their fifth decade of life.