Cranial Nerve VI Palsy as Presenting Sign of Previously Undiagnosed Metastatic Prostate Adenocarcinoma to the Clivus.

Prostate adenocarcinoma is the most common malignancy in males in the United States and is typically highly treatable. Herein we present a case report of a male with a history of prostate adenocarcinoma previously managed with definitive radiation therapy who presented with sudden onset diplopia and examination consistent with an abducens palsy. He was ultimately found to have prostate adenocarcinoma metastatic to the clivus causing cranial neuropathy, and was referred for systemic chemotherapy and palliative Cyberknife stereotactic radiosurgery. While relatively rare, metastatic disease should be included in the differential diagnosis of atypical skull base lesions.