Carotid sinus syndrome associated with an occult primary nasopharyngeal carcinoma.

A patient presented with syncope, and a diagnosis of carotid sinus syndrome was established. Further evaluation revealed a large nasopharyngeal carcinoma invading the left petrous bone. There were no cervical metastases. The tumor partially regressed with radiation therapy, and there was complete resolution of the carotid sinus syndrome, but the patient died three months later of metastatic disease. Autopsy confirmed petrous bone involvement by the mass but no cervical metastatic disease. This is the first reported case (to our knowledge) of malignancy-associated carotid sinus syndrome attributable to a primary nasopharyngeal carcinoma. The literature on malignancy-associated carotid sinus syndrome is reviewed, with emphasis on pathophysiology and treatment.