Multifocal intravestibulocochlear and intracranial vestibular schwannomas: illustrative case.

backgroundEighth cranial nerve schwannomas represent a rare pathological condition, and their sporadic unilateral multifocal presentation is even more uncommon. Here, the authors present a rare case of multifocal intravestibulocochlear and intracranial vestibular schwannomas (VSs) and review analogous cases in the existing literature. OBSERVATIONS: A 54-year-old female patient presented to the authors' clinic in March 2024 with complaints of left-sided hearing loss, tinnitus, and vertigo. Gadolinium-enhanced MRI revealed a Koos grade III VS localized in the cerebellopontine angle (CPA) with extension in the internal auditory canal and a coexisting intravestibulocochlear schwannoma. CT imaging showed no cochlear fundus dilatation or bone erosion. The patient underwent a left transotic approach with blind sac closure of the external auditory canal. No continuity was observed between the inner ear and intrameatal-CPA VSs, confirming the presence of two distinct lesions. LESSONS: This case emphasizes the importance of a preoperative radiological evaluation and the necessity of a multidisciplinary team to ensure optimal surgical treatment and complete tumor resection. https://thejns.org/doi/10.3171/CASE25116.