C1. A “ Ping-Pong ” Ball Left Atrial Thrombus Mimicking Left Atrial Myxoma : A Case Report

Background Valvular heart disease has a high prevalence, especially in developing countries, even though there is actually no exact number for prevalence in Indonesia. The prevalence of left atrial thrombus is around 17% in patients with severe mitral stenosis and will increase about 2 times in patients with atrial fibrillation. Although left atrial thrombus is common in mitral stenosis, left atrial thrombus mimicking myxoma is rarely reported Case Summary 47-year-old woman came to Dr. Soetomo cardiology outpatient clinic. She complained of palpitation and shortness of breath. Her electrocardiogram was showed atrial fibrillation. Echocardiography showed severe mitral stenosis and free moving, round shape, left atrial mass. She then immediately planned for Mitral Valve Replacement (MVR) surgery and evacuation of the mass. We found a solid wall spherical mass, layered and easily separate. Microscopic examination revealed extensive fibrin, hemorrhage and mononuclear inflammatory cells with the conclusion of a thrombus Discussion Left atrial thrombus and myxoma often look the same on echocardiography, especially when the thrombus is free-moving and round shape. Echocardiography in this case showed a free-moving mass, round shape, like a "ping-pong" ball. The mass also has solid wall suggesting a myxoma. After surgery, we found tha the mass is multilayered which looks like a myxoma. However, microscopically confirmed that the mass is a thrombus. This suggests that a left atrial thrombus may mimicking a myxoma on echocardiography. Therefore, the gold standard for diagnosing intracardiac mass is by histopathology