Aneurysm of atrial septum associated with rheumatic mitral stenosis simulating tumour of right atrium.

We present a case of aneurysm of interatrial septum associated with rheumatic mitral stenosis, which supports the theory that claims that the pressure gradient between the atriums plays an important part in its aetiology. The angiographic image of a filling defect in the right atrium may cause an erroneous diagnosis of atrial tumour. The levophase of right angiography and cross-sectional echocardiography confirmed the diagnosis of aneurysm of interatrial septum.