Cerebellopontine angle metastasis of a parotid mucoepidermoid carcinoma arising from perineural invasion along the facial nerve.

A 72-year-old male was referred with left sided hearing loss, tinnitus and disequilibrium with radiological appearances suggestive of an intracanalicular left vestibular schwannoma. The patient then developed left sided trigeminal nerve sensory loss over the next 9 months with an enlarging parotid swelling. The eventual diagnosis was a destructive lesion in the left cerebellopontine angle (CPA) arising from metastatic perineural invasion along the facial nerve by a parotid mucoepidermoid carcinoma. Surgical resection and targeted beam radiotherapy achieved a survival period of 9 months.