[Left atrial thrombus without mitral disease; report of a case].

A 76-year-old man was admitted to our hospital because of surgical treatment for mass in the left atrium(LA). Echocardiography and computed tomography(CT) revealed mobile mass in LA which had stalk at the left atrial appendage. It was difficult to distinguish myxoma from thrombus. LA mass has risk of sudden circulatory collapse and systemic emboli, so it is indicated for emergent operation. Mass resection with appendage was performed through the transseptal superior incision using cardiopulmonary bypass. Pathological diagnosis was thrombus. Most of LA thrombus were complicated with mitral stenosis, LA thrombus without mitral disease is rare. A few authors reported the useful of CT and echocardiography, but we could not lead to precise diagnosis from preoperative image.