Rapid growth of acoustic neuromas after stereotactic radiotherapy in type 2 neurofibromatosis.

We describe a rare complication of stereotactic radiotherapy for large acoustic neuromas in a patient with type 2 neurofibromatosis. We retrospectively reviewed the case of a 14-year-old girl who had been referred to our tertiary care center. Prior to referral, the patient had been evaluated for hoarseness. During the work-up, magnetic resonance imaging (MRI) detected two large bilateral acoustic neuromas and two bilateral jugular foramen tumors. The patient was diagnosed with type 2 neurofibromatosis, and she underwent stereotactic radiotherapy for treatment of the two acoustic neuromas; the jugular foramen tumors were not irradiated. The patient's post-treatment course was complicated by hydrocephalus and symptoms of brainstem compression, which required urgent surgical intervention. Follow-up MRI 7 months following radiotherapy demonstrated a rapid growth of the acoustic neuromas, but no appreciable change in the size of the jugular foramen neuromas. These findings suggest that the radiotherapy might have been the cause of the rapid growth of the acoustic neuromas. To our knowledge, no such report has been published in the literature, and this phenomenon might be unique. Our findings suggest that radiotherapy might not be the optimal first-line treatment for acoustic neuromas in patients with type 2 neurofibromatosis.