Bilateral acoustic tumors. A diagnostic and surgical challenge.

Bilateral acoustic tumors present problems not only in diagnosis but in surgical correction as well. The usual auditory findings associated with acoustic tumors occur late in the development of these lesions. Although vertigo usually is not a complaint, electronystagmographic caloric vestibular tests often show reduced or absent responses bilaterally. In contrast to unilateral-type tumors, bilateral tumors are invasive. Thus, total removal often is not accomplished. However, it is our suspicion that the interruption of the blood supply to the residual tumor causes it to remain dormant.