Right atrial thrombus arising from the junction of the right atrium and the inferior vena cava

Abstract Background Cardiac tumors are a rare cause of recurrent syncope which are detected on echocardiography, computed tomographic scan, and/or magnetic resonance imaging. We present echocardiographic, anatomic, and histopathologic images of a cardiac tumor arising from the junction of the right atrium and the inferior vena cava in a young lady. Methods Transthoracic echocardiography, transesophageal echocardiography, postmortem examination (autopsy), and histopathology. Results Transesophageal echocardiogram showed a 7×3-cm mobile multilobulated right atrial mass arising from the right atrial wall near the inferior vena cava. The patient was admitted to hospital to undergo cardiac surgery; however, unfortunately, she went in to cardiorespiratory arrest on the eve before surgery. Autopsy showed embolized mass obstructing the main pulmonary trunk, and pathology revealed an old organizing thrombus. Conclusions Cardiac thrombi can mimic appearances of a myxoma on echocardiogram. Delay in thrombus removal surgery can result in increased mortality as seen in our case.