A 80-year-old woman underwent emergency operation for a type A early thrombosed aortic dissection associated with cardiac tamponade. Her preoperative chest CT (not enhanced) showed high density area in the false lumen that indicated early thrombosis and the projection of true lumen at antero-left-lateral portion of ascending aorta that means "ulcer-like projection" called on aortogram. After the relief of the cardiac tamponade by pericardiocenthesis, we emergently performed the graft replacement of the ascending aorta under the extracorporeal circulation combined with selective cerebral perfusion. Her postoperative course was uneventful and satisfactory.