Lung cancer mimicking acute myocardial infarction on electrocardiogram.

Myocardial involvement by malignant neoplasm is rare and often not clinically manifested. The diagnosis is usually made only at autopsy. A 71-year-old man with squamous cell lung cancer presented with chest discomfort. His electrocardiogram was diagnostic of acute myocardial infarction. However, because of the lack of classic symptoms and signs of acute myocardial infarction and normal serum levels of cardiac enzymes, an echocardiography was performed before initiation of thrombolytic therapy. The echocardiography showed a huge hyperechoic mass located in the posterolateral aspect of the left ventricle with myocardium invasion. Thrombolytic therapy was withheld. In patients with lung cancer, an electrocardiogram representative of acute myocardial infarction can rarely be induced by myocardial involvement with lung cancer.