Effective October 1, 2010, codes 237.73, Schwannomatosis, and 237.79, Other neurofibromatosis, were created for neurofibromatosis. Neurofibromatosis (NF) refers to a group of three distinct autosomal dominant genetic disorders that cause tumors to grow along the nerves.
NF type 1 (NF1) (237.71) is the most common type of neurofibromatosis and is also known as von Recklinghausen disease and peripheral fibromatosis. It affects 1 in 4,000 but 30% to 50% of new cases are spontaneous and of unknown cause. Common symptoms may be present at birth and are usually evident by age 10. They include multiple light-brown (cafÃ©-au-lait) spots on the skin, tumors of the peripheral nerve, freckling in the armpit or groin, abnormal development of the spine, cardiovascular complications and learning disabilities. NF1 is progressive. There is a normal life expectancy, but symptoms often worsen over time. Treatment involves relieving the symptoms.
Neurofibromatosis type II (NF2) (237.72) affects 1 in 40,000. The classic sign of NF2 is the development of bilateral vestibular tumors (schwannomas or acoustic neuromas) on the eighth cranial nerves that affect hearing and balance. Schwannomas may occur along any nerve of the body including spinal, cranial and peripheral nerves. As these tumors grow, they can cause serious disability requiring surgical removal. Symptoms of NF2 are seen between the ages of 18 to 22. The most common sign is hearing loss or ringing in the ears. While there are few studies on the prognosis, NF2 is known to increase the risk for other tumors of the nervous system such as glioma, meningioma and ependymoma. Surgical options depend on the size of the tumor.
When associated with the inherited form of the disorder, schwannomatosis (once considered a variation of NF2) has been identified as a rare mutation of the SMARCB1/INI1 gene. Schwannomas develop all over the body except on the vestibular nerve. As the tumors grow, they compress nerves and cause pain, numbness, tingling, weakness and other neurological symptoms. Symptoms occur over age 30. A third of the 1 in 40,000 individuals with schwannomatosis have tumors that are limited to a single part of the body such as a segment of the spine, leg or arm. The severity of pain and disability may require surgical removal or intervention to reduce the size of the tumor.