Giant biatrial myxoma in an atrial septal defect

Myxomas account for a majority of the reported primary cardiac tumors that are relatively rare, and biatrial myxomas in an atrial septal defect are extremely rare. Here, we present the case of a healthy 79-year-old woman who was referred to our hospital after a giant mass in the left atrium was incidentally detected by transthoracic echocardiography. Although she was asymptomatic, we surgically resected the mass soon after admission, considering the risk of embolism. During the surgery, we observed the giant bilateral tumor in an atrial septal defect, which was, on pathological evaluation, found to be a myxoma.