Schwannomatosis is a rare form of NF that has only recently been recognized and appears to affect around 1:40,000 individuals. As with NF1 and NF2, schwannomatosis may vary greatly between patients. Because of this, and because the population of individuals is so small and the disorder so recently characterized, these patients have, until recently, been hard to definitively identify. Therefore the draft diagnostic criteria below will continue to evolve as more cases are identified and studied.
People with schwannomatosis develop multiple schwannomas on cranial, spinal and peripheral nerves–but they do not develop vestibular tumors and do not go deaf. They also do not develop any other kinds of tumors (for example, meningiomas, ependymomas or astrocytomas) and do not have learning disabilities.
People with schwannomatosis have problems with chronic pain that often exceeds their neurological problems. The first symptom of schwannomatosis is almost always pain, which can occur in any part of the body. Many patients with schwannomatosis go several years before the source of their pain is realized because they have few or no neurological symptoms.