A case of cardiac calcified amorphous tumor complicated with acute myocardial infarction.

An 80-year-old woman with a history of eosinophilic granulomatosis with polyangiitis, cardiac hypertrophy, and diabetes called for an ambulance after developing chest pain. She was diagnosed with acute myocardial infarction (AMI), and coronary angiography revealed occlusion of the right coronary artery. Coronary aspiration was performed, and coronary aspirate was white with calcified factor. After percutaneous coronary intervention, transthoracic echocardiography performed on day 25 revealed a hyperechoic mobile mass originating from the anterior mitral leaflet. As a mobile or rapidly increasing mass carries a high risk of embolism, we decided to perform surgical resection. Preoperative cerebral magnetic resonance imaging showed asymptomatic cerebral infarction, suggesting embolism by the cardiac mass. Resection of the cardiac mass was performed by cardiac surgeons. Microscopic pathology of cardiac mass revealed nodules of calcification and fibroblasts, leading to diagnosis of calcified amorphous tumor (CAT). Furthermore, the microscopic pathology of the coronary aspirate showed calcification, fibrin, and vascular endothelial cells. The pathological similarity of the cardiac mass and coronary aspirate indicated that the AMI has been caused by CAT. CAT causes systemic embolization; however, only 1 case of MI caused by CAT has been reported. We therefore experienced a rare case in which CAT caused AMI. <Learning objective: This is a very rare case of acute myocardial infarction (AMI) caused by calcified amorphous tumor (CAT). When encountering AMI by embolism, the possibility of the involvement of CAT should be kept in mind. Careful observation of transthoracic echocardiography or transesophageal echocardiography, and a prompt decision concerning the indication for surgical treatment after assessing the risk of embolism are important.>.