In a 72-year-old patient with anemia (Hb 7 g/dl), duodenoscopy exhibited an area of polypous irregular-looking mucosa. Histology revealed duodenal infiltration by epithelioid tumor cells, immunhistochemically positive for endothelial cell markers (CD34, CD31, ERG). Ultrasonography showed thrombotic material in the otherwise unremarkable abdominal aorta with some uptake of contrast bubbles on CEUS. Histological and clinical diagnosis assumed an epithelioid angiosarcoma of the thoraco-abdominal aorta at the level of the visceral and renal arteries with duodenal metastases.To prevent further shedding of tumor cells and aortic rupture, a branched stent-graft was placed into the thoraco-abdominal aorta. Palliative chemotherapy with gemcitabine and docetaxel was started, leading to a partial remission after 6 cycles. Three months later, however, there was a progress of the duodenal masses with new pulmonal and osseous metastases. Thirteen months after the initial diagnosis, death occured due to a hemorrhagic shock caused by a hematothorax.Aortic tumors are exceedingly rare, with only slightly more than 220 cases reported so far. In most cases, diagnosis is made either at autopsy or after an emergency operation for embolic complications like embolic intestinal ischemia. With an overall median survival of 8 months, prognosis is very poor.This case sensitizes for the correct sonographic interpretation of aortic “thrombi” in an otherwise normally appearing aorta, possibly with the aid of CEUS. Besides, it demonstrates the relatively early and uncommon diagnosis of an aortic angiosarcoma by the combination of endoscopy, immunohistochemistry, and ultrasonography.