An uncommon cause of syncope.

The authors present a case of a man with recurrent syncopal episodes. The patient had been hospitalized twice before reaching a correct diagnosis. The syncope was originally ascribed to a sick sinus syndrome, which led to pacemaker implantation. Nonetheless, the patient relapsed with no evidence of pacemaker dysfunction, and was readmitted to the hospital where the likely cause for his symptoms was identified: an adenocarcinoma of the lung infiltrating the vagus and recurrent laryngeal nerves. No further syncopal episodes occurred after thoracic surgery. This syncope led to an early diagnosis of lung cancer leading to appropriate and life extending treatment.