Secondary carcinoma of left atrium simulating myxoma.

Three cases are presented in which secondary carcinoma in the left atrium mimicked atrial myxoma or infective endocarditis. Constitutional features of weight loss, fever, anaemia, leucocytosis, raised erythrocyte sedimentation rate, and systemic emboli were prominent clinical features. The association of these systemic manifestations with both secondary deposits in the atrium and atrial myxomata may be the result of an immune response to circulating tumour antigens. Mitral stenosis was present in two of the three patients suggesting that left atrial thrombus may provide a site for the seeding of malignant cells.