Differential Diagnosis of a Left Atrial Mass after Surgical Excision of Myxoma: a Remnant or a Thrombus?

Echocardiographic diagnosis of atrial myxoma may not always be straightforward, and the distinction between myxoma and thrombi is not easy, especially when we observe a mass after successful surgery. Our report describes a 72-year-old woman who presented with right upper limb hemiparesis and was subsequently diagnosed as having transient ischemic attack due to a left atrial myxoma. One month after successful surgical resection of the tumor, the patient developed left-sided weakness. Echocardiography revealed a left atrial mass attached to the interatrial septum. Intravenous heparin was administered as a therapeutic trial for postoperative thrombi, which resulted in a decrease in mass size within a week. Anticoagulation with warfarin was continued, and complete resolution was demonstrated on a 4-month follow-up transesophageal echocardiography. This case highlights the fact that thrombus formation at the surgical site should be considered an unusual but potential complication after surgical resection of left atrial myxomas.