Intracanalicular meningioma mimicking vestibular schwannoma.

SUMMARY: Three cases of intracanalicular meningioma mimicking vestibular schwannoma are presented. In each case, a contrast-enhancing mass filling the internal auditory canal was identified on MR images and was originally diagnosed as a vestibular schwannoma. Although it is difficult to differentiate definitively between these lesions preoperatively, imaging findings inconsistent with a diagnosis of vestibular schwannoma can be identified. Preoperative identification of intracanalicular meningiomas permits alterations in surgical planning that allow for the more complete resection of these rare tumors.