Three-dimensional transthoracic echocardiogram. TTE shows an irregular cystic mass with a pseudoaneurysm measuring 8.49*3.81 cm in size in the lateral wall of the right atrium, and the mass obviously compressed the right atrium. A defect was observed between the pseudoaneurysm and the right atrium. LA: left atrium; RA: right atrium; PA: pseudoaneurysm