Extracardiac Intrapericardial Mass Impersonating as Left Atrial Mass: Echocardiographic Perspectives.

Extracardiac intrapericardial masses arising posterior to left atrium (LA) often mimic an intracardiac LA mass on echocardiography. Although transthoracic echocardiography (TTE) is the primary screening tool to detect any cardiac mass, transesophageal echocardiography (TEE) is proven superior to TTE in delineating the size, morphology, and exact site of origin of LA masses. We report a case, where the preoperative TTE diagnosed an LA mass which was later confirmed to be an extracardiac intrapericardial mass by cardiac magnetic resonance imaging and intraoperative TEE. The mass was compressing the LA, and the timely diagnosis avoided the opening of the LA for mass excision.