Intimal sarcoma of the left atrium – A rare form of mitral valve obstruction

A 70-year-old woman was referred to the emergency department due to mild effort dyspnea, weight loss and night sweats. Transthoracic and transesophageal echocardiography revealed dilated left atrium with an extensive multilobulated mass infiltrating the left atrial posterolateral wall. It prolapsed through the mitral valve during diastole, resulting in elevated mean and peak pressure gradients (8 mmHg and 25 mmHg, respectively [Panels A-C]). Coronary angiography revealed a highly vascularized mass (Panel D, Video 1). Cardiac magnetic resonance (CMR) evidenced the full extension of the mass -measuring 10 cm -in relation to the left atrial posterolateral wall. It extended to both inferior pulmonary veins and revealed tissue characteristics in T1(isointense) and T2-weighted (hyperintense) images. No contrast uptake was found during first-pass perfusion, but progressive and heterogeneous uptake was observed in the early and late gadolinium enhancement (LGE) images, with a low signal intensity central area (Panels E-G, Video 2 and 3). Computed tomography (CT) staging was negative for