Acoustic neuroma in an adolescent without neurofibromatosis: case study

When acoustic neuromas are found in younger age groups, they are typically bilateral and associated with neurofibromatosis (NF). A unilateral acoustic neuroma in a child or adolescent without NF is rare. We report audiometric, auditory brainstem response (ABR) and magnetic resonance imaging (MRI) data for a 15-year-old male with an acoustic neuroma but without associated NF. The patient was seen for audiologic assessment on three separate occasions over a period of 5 years. The first two assessments produced unremarkable audiometric and immittance data. The third assessment, subsequent to a failed school hearing screening, demonstrated a flat unilateral sensorineural hearing loss, unilateral absent acoustic reflexes, and abnormal bilateral ABR recordings. MRI with contrast demonstrated a unilateral mass extending out of the internal auditory meatus. Microscopic examination of the removed tumor confirmed a vestibular schwannoma. An enhanced MRI 3 years post neuroma removal demonstrated no evidence of tumor regrowth and no evidence of other neoplasms. ABR recordings for the uninvolved ear continued to demonstrate neural synchrony as evidenced by normal absolute wave latencies; however, the III-V and I-V interwave latencies remained extended beyond the 99th percentile. Postoperatively, the young man was fitted with a high gain in-the-ear hearing aid in the involved ear, which he has continued to wear on a daily basis for the past 3 years.