Case report of a sub-occluding thrombus in thoracic aorta: what is the origin?

Aortic thrombosis represents a consequence of atherosclerotic disease. In few cases, it can be secondary to large vessel or infective vasculitis. More rarely, aortic thrombosis is the manifestation of a primary malignant neoplasm of the aortic wall. Aortic angiosarcoma is a rare tumour, its clinical presentation is often non-specific and associated signs and symptoms may vary greatly. An early diagnosis is difficult to reach and the presence of metastatic disease is not uncommon at the time of diagnosis. The prognosis is poor overall.

We report the case of a female patient who presented to her GP because of fatigue, hyporexia, weight-loss, and anaemia. An ultrasound of the abdomen showed two small pancreatic lesions, confirmed and described as benign cystic pancreatic lesions on computed tomography (CT) imaging; an incidental thrombus in the superior mesenteric artery was also found on CT imaging. The thoracic CT identified a large thrombotic lesion in the descending thoracic aorta with significant narrowing of the aortic lumen and confirmed the presence of an osteolytic bone lesion on the VIII right rib, in the absence of atherosclerotic disease. Signs of increased metabolic activity in the aortic lumen and in the VIII posterior right rib were shown at a subsequent positron emission tomography. A CT-guided biopsy of the bone lesion was performed and at histology the diagnosis of metastatic angiosarcoma of the aortic wall was made.

Aortic angiosarcoma is a rare cause of aortic thrombosis, to be taken into consideration in a patient with thrombotic lesions of the aorta in the absence of atherosclerotic disease. The differential diagnosis is difficult because of clinical presentation and radiological features similar to those of inflammatory aortic disease. In our case, the final diagnosis of angiosarcoma was made only by a biopsy of a bone metastatic lesion.