[Calcified amorphous tumor of the right atrium after open heart surgery; report of a case].

A 37-year-old woman, who had undergone surgery of atrial septal defect (ASD) at 12-year-old, developed bradycardia and referred to our hospital. Transthoracic echocardiography revealed high echoic tumor in the right atrium. The image of the tumor was of low intensity by T2 weighted magnetic resonance imaging (MRI) and floating mass with a stalk to the right atrium in cine MRI. She underwent tumor resection under cardiopulmonary bypass. Histopathologilal examination of the tumor was calcified amorphous tumor. The postoperative course was uneventful.