AbstractTwo patients with metastatic carcinoma (one cervical and one testicular) in whom echocardiography was instrumental in diagnosing a right ventricular cavity mass are presented. In the first case the M‐mode echocardiogram revealed dense echoes in the right ventricle and right ventricular outflow tract during systole and diastole. Surgical confirmation of the mass lesion was obtained. The second case also revealed abnormal echoes in the right ventricle and right ventricular outflow tract, but they were less dense and distinct. Two‐dimensional echocardiography clearly delineated a highly mobile mass of tissue in the right ventricle which corresponded to the necropsy findi