Malignant vestibular schwannoma with intracerebral metastasis.

Malignant change in vestibular schwannoma is rare and intracranial metastatic deposits have not been reported. We report the case of a 64 year old woman with a benign vestibular schwannoma who underwent translabyrinthine excision in 1996 and Gamma Knife^® radiosurgery (Elekta AB, Stockholm, Sweden) (GKRS) in 2006. She presents 10 years after GKRS with progressive neurological deterioration. Histopathologic analysis confirms a malignant peripheral nerve sheath tumour, WHO grade IV with subsequent metastatic spread to the left thalamus confirmed on biopsy. We report a rare case of a vestibular schwannoma metastasizing with histological confirmation. It also reminds us of malignant conversion of a benign vestibular schwannoma following GKRS and subsequent aggressive behaviour, with poor prognosis. [ABSTRACT FROM AUTHOR]