Abstract
A man in his 50s with sudden-onset left-sided subcostal pain was diagnosed with splenic infarction by thoracoabdominal CT with contrast enhancement, which also revealed a mural thrombus in the thoracoabdominal aorta, raising the possibility of aortic dissection. The electrocardiographic findings were normal and transthoracic echocardiography did not detect thrombus in the heart. Antihypertensive medication was administered on admission, and anticoagulation therapy was started after he developed left renal infarction and occlusion of the superior mesenteric artery. Nevertheless, he subsequently sustained an acute cerebral infarction. Transoesophageal echocardiography revealed an abnormal floating structure in the ascending aorta, which was surgically removed and finally diagnosed as an organising thrombus. Although most of the causes of multiorgan infarction are cardiogenic, floating mural thrombus can also be a cause. Anticoagulation therapy may be necessary for patients with recurring severe embolisms even when aortic dissection has not been completely ruled out.