Hearing improvement in a growing vestibular schwannoma.

Vestibular schwannomas are benign, slow-growing tumors that originate from Schwann cells lining the vestibular nerves, most commonly the superior vestibular nerve. They arise at the neurilemmal/neuroglial junction which is situated within the internal auditory canal. They have an incidence of 1 per 100,000 per year and a prevalence of around 700 per million. A case of a patient undergoing a period of observation for a vestibular schwannoma whose hearing improved despite growth of the tumor is described. This raises interesting questions regarding the pathophysiology of hearing loss in patients with vestibular schwannomas. Possible hypotheses are discussed.