ABSTRACT
Spontaneous echo contrast [SEC] and thrombus in enlarged left atrium [LA] are common in mitral valvular disease [MVD] and SEC is considered to be a prethrombotic condition. Reliable exclusion of LA thrombus is important before any definitive curative attempts like percutaneous transluminal mitral commissurotomy [PTMC], closed mitral commissurotomy [CMC] or innovative therapies like pulmonary vein isolation and percutaneous closure of the LA appendage. Echocardiography, particularly the transesophageal echocardiography [TEE] is considered to be the gold standard for the diagnosis and to exclude LA thrombus. However, LA thrombus may remain rarely undetected even by TEE potentially making the interventions a risky job. We present a case of mitral stenosis [MS] with giant LA where profuse, dense SEC masked the underlying thrombus in the LA cavity