Cardiac pseudomass due to enlarged epicardial adipose tissue: Comparison of echocardiography and cardiac magnetic resonance imaging.

A 75-year-old woman underwent preoperative echocardiography, which revealed a mass in the left atrium; however, cardiac magnetic resonance imaging showed no mass. Echocardiography revealed an enlargement of the epicardial adipose tissue in the left atrioventricular groove, therefore a pseudomass. Causes of cardiac pseudomass on echocardiography have been reported. Suspected pseudomasses should be reliably differentiated from a tumor or thrombus, and if new forms are found, the images must be shared for the benefit of clinicians.