Metastatic melanoma causing complete atrioventricular block--the role of FDG PET/CT in diagnosis.

Cardiac involvement with melanoma is not uncommon, but only a few are reported to have antemortem diagnosis. Here, we report a case of a patient with melanoma causing complete atrioventricular block, which is a rare complication of this condition. The patient had multiple metastatic lesions from melanoma and had undergone multiple surgeries and later developed asystole which was treated with a pacemaker. Echocardiogram was performed but no metastatic lesion suggested or detected. Cardiac metastasis was not suspected until 5 months later when the patient underwent a FDG PET/CT for a whole-body evaluation which was interpreted to be suspicious for metastasis to the myocardium. This was confirmed by a repeat myocardial FDG PET scan. In this case report, the role of FDG PET in melanoma patients with cardiac involvement is discussed.