Neurofibromatosis 2 (bilateral acoustic neuromas).

The hallmark of neurofibromatosis 2 is the presence of bilateral acoustic neuromas. In families that carry the neurofibromatosis 2 gene, bilateral acoustic neuromas are inherited in an autosomal-dominant pattern, with penetrance of more than 90%. The risk that any offspring of an affected parent will develop these tumors is approximately 50%. [1]

When clinical and familial findings suggest a diagnosis of neurofibromatosis 2, magnetic resonance imaging (MRI) of the head should be performed to search for acoustic neuromas or other intracranial tumors. To detect small acoustic neuromas, especially intracanalicular ones, MRI is the most sensitive modality (figure).

An early diagnosis of acoustic neuroma affords the best opportunity for a successful treatment with the least risk to facial and cochlear nerve function. [2]

From the Department of Radiology, MacNeal Hospital, Berwyn, Ill.

References

(1.) Martuza RL, Eldridge R. Neurofibromatosis 2 (bilateral acoustic neurofibromatosis). N Engl J Med 1988;318:684-8.

(2.) Gillespie JE. Imaging in neurofibromatosis type 2: Screening using magnetic resonance imaging. Ear Nose Throat J 1999;78:102-3, 106, 108-9.