{Reference Type}: Case Reports {Title}: Primary thoracic aorta angiosarcoma presenting with thromboembolism and progressive claudication despite anticoagulation. {Author}: McKenzie J;Chander S;Mitchell C;Lewin J; {Journal}: J Med Imaging Radiat Oncol {Volume}: 68 {Issue}: 4 {Year}: 2024 Jun 19 {Factor}: 1.667 {DOI}: 10.1111/1754-9485.13642 {Abstract}: Primary aortic angiosarcomas (PAA) are rare angiosarcomas, frequently diagnosed in advanced stages due to initial misdiagnosis. This case describes a 66-year-old woman, initially presenting with a distal thoracic aorta thrombus and symptomatic bilateral popliteal emboli. Despite initial management and therapeutic anticoagulation, she experienced progressive lower limb claudication and 12 months following initial presentation she re-presented with an obstructing distal thoracic aorta mass and metastatic disease. Histopathology confirmed metastatic epithelioid angiosarcoma. Despite urgent palliative radiotherapy, she died 6 weeks after diagnosis from complications of tumour thromboembolism. Suspicion for PAA should be raised in the case of thrombus in atypical segments (e.g. thoracic aorta) or progressive course despite anticoagulation. Multimodal imaging including MRI and FDG-PET is useful to distinguish from benign aetiologies.