Abstract

Intracardiac masses are rare but may pose significant diagnostic and therapeutic challenges because of their heterogeneous etiologies and variable clinical presentations. We report a case of a large left atrial mass detected in a 77-year-old male patient who presented with dyspnea and palpitations and was found to have newly diagnosed atrial fibrillation. Transthoracic echocardiography revealed a mobile, hyperechoic mass measuring 2.6×4.3 cm within the left atrium. The mass protruded toward the left ventricle during systole in association with mitral valve motion and partially obstructed left ventricular filling. Given the absence of the mass on previous echocardiographic examinations, the lack of prior anticoagulant therapy, and the recent onset of atrial fibrillation, an intracardiac thrombus was considered the most likely diagnosis. Although surgical intervention was recommended, the patient declined the procedure. Consequently, the patient was managed with oral anticoagulation therapy and scheduled serial echocardiographic follow-up. This case underscores the central role of echocardiography in the diagnostic evaluation of intracardiac masses and highlights the importance of an individualized treatment strategy based on integrated clinical and imaging findings in selected patients.