RESUMO
Left atrial thrombi are a significant cause of cardioembolic morbidity and mortality. Transesophageal echocardiography is the preferred method for complete visualization of atrial thrombi, and has a sensitivity and specificity of up to 100% and 99%, respectively. Cardiac magnetic resonance imaging has been shown to be useful in identifying tissue characteristics that may aid in differentiating between atrial myxoma and thrombi. This is an unusual case of a large, free-floating atrial thrombus with a cystic appearance that was surgically removed. The echocardiographic appearance of the cystic atrial mass led to the consideration of another potential etiology for a cardiac mass, namely, atrial myxoma. Histopathologic analyses of the mass led to the final diagnosis of an atrial thrombus.
