Giant left atrial thrombus: an unexpected finding.

The incidence of left atrial thrombi is higher in patients with mitral valve stenosis. Its presence and location have important implications in deciding on the therapeutic approach, particularly the need for valve repair. We describe the case of a 63-year-old patient, with asymptomatic moderate mitral stenosis, hospitalized due to community-acquired pneumonia, in whom investigation to exclude pulmonary thromboembolism revealed a giant left atrial thrombus, which required urgent surgery.