A 50-year-old asymptomatic man was referred for cardiovascular magnetic resonance after the incidental finding of a mediastinal mass on echocardiography. In particular, the echocardiogram showed a mediastinal mass (6.5×10 cm) close to the right side of the heart without clear infiltration. Left and right ventricular function was normal. The chest x-ray showed the right-sided mediastinal mass obliterating the right heart border, with normal lung parenchyma. The ECG (Figure 1) showed sinus rhythm with normal atrioventricular conduction, left axis deviation, normal intraventricular conduction, and normal repolarization. The cardiac magnetic resonance confirmed the presence of a large encapsulated mediastinal mass (Figure 2) located superiorly in the right anterior mediastinum, adjacent to the ascending aortic wall, the superior vena cava, and the junction of the right ventricle outflow tract with the main pulmonary trunk. There was some compression of the right upper pulmonary vein but no …