Embryonal carcinoma of the testis presenting as a left heart mass. A 31-year-old man with a history of intravenous drug abuse and tooth abscess was admitted for evaluation of possible infective endocarditis. Echocardiography showed that he had a left atrial mass. The mass removed from the left atrium had the same histology as the primary embryonal carcinoma discovered in the right testicle during hospitalization. The patient made a smooth recovery after surgical intervention and chemotherapy. This is believed to be the first reported case of metastasis from embryonal carcinoma of the testis to the left side of the heart that was successfully removed at surgery. 