Diagnosis and treatment of a left atrial myxoma originating from an atrial septal defect closure device: a case report.

Background: Ostium secundum atrial septal defect (osASD) is a common congenital heart disease and transcatheter closure is the preferred treatment. Late device-related complications include thrombosis and infective endocarditis (IE). Cardiac tumours are exceedingly rare. The aetiology of a mass attached to an osASD closure device can be challenging to diagnose. Case summary: A 74-year-old man with atrial fibrillation was hospitalized for evaluating a left atrial mass discovered incidentally 4 months earlier. The mass was attached to the left disc of an osASD closure device implanted 3 years before. No shrinkage of the mass was observed despite optimal intensity of anticoagulation. We describe the diagnostic workup and management of the mass that at surgery turned out to be a myxoma. Discussion: A left atrial mass attached to an osASD closure device raises the suspect of device-related complications. Poor endothelialisation may promote device thrombosis or IE. Cardiac tumours (CT) are rare, and myxoma is the most common primary CT in adults. Although no clear relationship exists between the implantation of an osASD closure device and a myxoma, the development of this tumour is a possible occurrence. Echocardiography and cardiovascular magnetic resonance play a key role in the differential diagnosis between a thrombus and a myxoma, usually identifying distinctive mass features. Nevertheless, sometimes non-invasive imaging may be inconclusive, and surgery is necessary to make a definitive diagnosis.