Radiation-induced cavernous malformation within a vestibular schwannoma: A case report.

Cavernous malformations are a well-described complication of intracranial radiation; however, have only once previously been described within a vestibular schwannoma following radiotherapy. We report a case of a 78-year-old woman presenting with new hemifacial spasm 16-years following fractionated radiotherapy for a vestibular schwannoma, with imaging suggesting the formation of a cavernous malformation within the tumor. The patient underwent translabyrinthine resection, with final pathology confirming the diagnosis of a cavernous malformation within the vestibular schwannoma. This case highlights the need to maintain a broad differential in patients with new symptoms following radiotherapy for vestibular schwannomas, including hemifacial spasm. Cavernous malformations should be considered among potential radiation-related complications in patients with vestibular schwannoma. Level of Evidence: IV.