Neurofibromatosis 1 (Recklinghausen Disease) and Neurofibromatosis 2 (Bilateral Acoustic Neurofibromatosis)

doi:10.1059/0003-4819-113-1-39

Neurofibromatosis 1 (Recklinghausen Disease) and Neurofibromatosis 2 (Bilateral Acoustic Neurofibromatosis)

An Update

Abstract

The neurofibromatoses comprise at least two autosomal dominant disorders affecting an estimated 100 000 Americans with clinical manifestations that may require care from every type of clinician. Neurofibromatosis 1 and neurofibromatosis 2 have in common the occurrence of many neurofibromas but are distinctly different clinical disorders. The disease genes are on different chromosomes. Magnetic resonance imaging, particularly with gadolinium enhancement, has generally supplanted other techniques for visualizing brain, spinal, and other neural tumors in both disorders. The technique has rekindled the controversy over the nature and frequency of optic pathway tumors in patients with neurofibromatosis 1 and has revealed, throughout the brains of young patients, bright lesions that have uncertain clinical consequences and unknown pathologic bases. In patients with neurofibromatosis 2, small acoustic neuromas can be seen, leading to the possibility of excision with preservation of hearing and facial nerve function. Abnormal hearing may occur to excess in patients with neurofibromatosis 1, but acoustic neuroma has never been documented. In patients with neurofibromatosis 2, a battery of audiologic tests has a high positive predictive power. Lisch nodules or iris hamartomas, probably a universal sign in adults with the neurofibromatosis 1 gene, cause no problem with vision. Posterior capsular lens opacity in patients with neurofibromatosis 2 is a helpful diagnostic sign and a potential source of additional handicap in persons at risk for impaired hearing. Progress in the clinical delineation of the disorders has been matched with considerable research into the still obscure pathogenesis of the disorders. Such rapid advances may necessitate reconsideration of the conclusions of the National Institutes of Health Consensus Development Conference on Neurofibromatosis, especially those on the categories of persons in which a neurofibromatosis should be considered and the need for caution in recommending surgery. Watchful waiting may often be the best management for acoustic neuromas in neurofibromatosis 2.

Article and Author Information

An edited summary of a Clinical Staff Conference held 5 April 1989 at the Amphitheater, Building 10, Bethesda, Maryland. The conference was sponsored by the National Institutes of Health, U.S. Department of Health and Human Services.
Authors who wish to cite a section of the conference and specifically indicate its author may use this example for the form of reference:

Parry DM. Gene mapping and tumor genetics, pp 41-42. In: Mulvihill JJ, moderator. Neurofibromatosis 1 (Recklinghausen disease) and neurofibromatosis 2 (bilateral acoustic neurofibromatosis): an update. Ann Intern Med. 1990;113:39-52.
Requests for Reprints: John J. Mulvihill, MD, Department of Human Genetics, University of Pittsburgh, Crabtree Hall A300, 130 DeSoto Street, Pittsburgh, PA 15261.
Current Author Addresses: Dr. Mulvihill: Department of Human Genetics, University of Pittsburgh, Crabtree Hall A300, 130 DeSoto Street, Pittsburgh, PA 15261.

Dr. Parry: Clinical Epidemiology Branch, National Cancer Institute, National Institutes of Health, Executive Plaza North, Room 400, Bethesda, MD 20892.

Dr. Sherman: Wheaton Magnetic Imaging, 2801 University Boulevard, Kensington, MD 20895.

Ms. Pikus: Audiology Clinic, National Institute of Deafness and Other Communication Disorders, National Institutes of Health, Building 10, Room 5C306, Bethesda, MD 20892.

Dr. Kaiser-Kupfer: Clinical Branch, National Eye Institute, National Institutes of Health, Building 10, Room 10N226, Bethesda, MD 20892.

Dr. Eldridge: Neuroepidemiology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Federal Building, Room 710, Bethesda, MD 20892.