Acute myocardial infarction due to malignant neoplastic coronary embolus

A 54-year old man was diagnosed with right lung carcinoma (squamous cell carcinoma, SCC), stage IIIB (c-T2N3M0). Transthoracic echocardiography (TTE) showed a huge 8.9 cm × 1.3 cm tumor in the left atrium (LA) that was invaded by a pulmonary vein, and the tumor moved under the mitral valve at LA systole. After 3 months, he was diagnosed with acute myocardial infarction (AMI) and emergency coronary angiography (CAG) was performed. CAG showed that the distal segment of the right coronary artery was totally occluded. TTE showed that the shape of the mass tip became sharp. He was discharged on hospital day 15. He died 4 months after discharge because of right lung carcinoma with respiratory failure. An autopsy showed that the cause of AMI was tumor embolism. SCC clearly occupied a blood vessel lumen in the distal segment. This is a rare case of AMI due to embolism of lung carcinoma during progression of the disease with direct invasion to the LA. TTE is useful for assessing lung carcinoma invasion.