Abstract 13016: Tumor or Thrombus?: Intracardiac Thrombus Masquerading as a Tumor

Abstract

Introduction: Intracardiac masses comprise thrombi, vegetations, and tumors. Multimodality imaging modalities are often relied upon for a definitive diagnosis. We present a case of a left ventricular (LV) thrombus with characteristic of on contrast echocardiography that thrombus based on cardiac MRI. The mass resolved with anticoagulation. Case: A 56-year-old male with non-ischemic cardiomyopathy was admitted for management of decompensated heart failure. Transthoracic echocardiography (TTE) showed reduced left ventricular ejection fraction of 20 to 25% with diffuse hypokinesis. There was a newly detected large intracardiac mass seen in the left ventricle (figures 1-3) that enhanced with echocardiographic contrast (figure 2). Delay enhancement imaging on cardiac MRI, however, revealed a hypodense mass suggestive of a thrombus (figure 3). The patient started anticoagulation. An echocardiogram performed a month later revealed complete resolution of mass, confirming the thrombotic nature of mass (figure). Discussion: Contrast enhancement echocardiography is very helpful for characterization of intra-cardiac masses. Tumors usually enhance with contrast while thrombi are generally dark. Our case is unusual, the cardiac mass hyper-enhanced with echocardiographic contrast but had thrombus-like characteristics on cardiac MRI. The mass was proven to be a thrombus over time since it resolved with anticoagulation. Echocardiographic contrast usually fails to penetrate hard, chronic thrombi. However loosely structured, fresh thrombi may allow some passage of contrast. This has been demonstrated in carefully conducted in-vitro studies showing that imaging characteristics of newly formed thrombus is often bright with echocardiographic contrast. This underscores the importance of multi-modality imaging to diagnose the nature of a cardiac mass.