Positive 99mTc-stannous pyrophosphate myocardial image in a patient with carcinoma of the lung.

A "false-positive" 99mTc-stannous pyrophosphate (99mTc-PYP) myocardial image was seen in a patient with epidermoid carcinoma of the lung. The location of the increased activity corresponded to an area of direct invasion of the heart by carcinoma with associated multiple microscopic foci of myocardial necrosis. Metastatic carcinoma with myocardial necrosis should therefore be considered as a possible cause of a positive 99mTc-PYP myocardial image.