As many as 31% of patients with nasopharyngeal carcinoma present with intracranial extension. Despite this high percentage, extension to the cerebellopontine angle is rare. The mechanism of tumor spread to the cerebellopontine angle is not completely understood. The most likely mechanism is direct extension to the skull base with involvement of the petrous apex and further extension posteriorly via the medial tentorial edge. We report the case of a 46-year-old woman with nasopharyngeal carcinoma who had been treated initially with chemoradiation and subsequently with stereotactic radiosurgery for residual tumor. One year later, she presented with an intracranial recurrence of the nasopharyngeal carcinoma in the cerebellopontine angle; the recurrence mimicked a benign tumor on magnetic resonance imaging. The tumor was ultimately diagnosed as an undifferentiated carcinoma of nasopharyngeal origin. She was treated with palliative chemotherapy.
Nasopharyngeal carcinoma commonly arises from the fossa of Rosenmüller. The proximity of the skull base allows the tumor easy access to intracranial structures. Tumor extension into the cranial cavity can occur via perineural spread into the preformed foramina or by direct invasion of the skull base.1 A tumor in the cranial cavity has the potential to invade intracranial structures, but nasopharyngeal carcinoma involving the cerebellopontine angle is rare.2