A patient with rheumatic mitral stenosis and an atrial myxoma.

A 34-year-old woman with exertional dyspnoea and clinical diagnosis of mitral stenosis underwent echocardiographic evaluation. Moderate to severe rheumatic mitral stenosis was confirmed but an unsuspected mass lesion in the dilated left atrium attached to inter-atrial septum in fossa ovalis region was found. Although the attachment was in favour of myxoma, it was difficult to differentiate with certainty between left atrial myxoma and thrombus. Warfarin was prescribed but after 1 year the mass lesion remained unchanged. Both the severity of the mitral stenosis and the presence of the mass lesion led to our decision to proceed with surgery. Pathology showed typical histology of a myxoma.