A case of thrombus of the descending aorta successfully diagnosed on preoperative endoscopic ultrasonography.

A 45-year-old woman presented with left lower abdominal pain. A plain CT scan showed a slightly high-density, cord-like structure extending from the level of the diaphragm of the descending aorta to the superior mesenteric artery. Transgastric endoscopic ultrasonography (EUS) revealed a floating mass, smoothly attaching to the aortic intima and depicted as a hyperechoic region containing a mixture of hyperechoic and hypoechoic areas. EUS elastography revealed that the body of the mass consisted of medium soft tissue, with hard tissue at its base. On histopathological examination after surgery, the mass was found to consist mainly of fibrin, with no atypical cells. EUS examination should be used for the differential diagnosis between thrombi and tumors in the aorta.