Double localization of a unilateral sporadic vestibular schwannoma.

Vestibular schwannoma may present as a sporadic or genetically-based multi-localized benign neoplasm of the internal auditory canal and/or cerebello-pontine angle region. Multiple localization is generally regarded as genetic in origin and often affects the stato-acoustic bundle on both sides. A case of double vestibular schwannoma localized on the same stato-acoustic bundle is presented. After removal, slight histological differences were found between the two separate masses. From these findings, the possibility of a unilateral multiple localization of a vestibular schwannoma is considered plausible within the range of clinical presentation, with negative genetic features. Whether these individual masses might have an autonomous origin or a different growth pattern remains to be fully elucidated.