Angiosarcoma of the popliteal artery presenting as recurrent thrombosed aneurysm and hemorrhage in a young adult: a case report

Angiosarcoma of peripheral arteries is exceptionally rare and may mimic common vascular entities such as thrombosed aneurysm. This case highlights diagnostic pitfalls and perioperative challenges. A 34-year-old man presented with abrupt severe pain and acute ischemia of the left leg. Ultrasound and CT angiography suggested a 40-mm thrombosed popliteal artery aneurysm. Histopathology after subsequent reoperations revealed high-grade angiosarcoma of vascular endothelial origin (CD31/CD34 positive). During the index admission, the patient underwent urgent autologous vein bypass with exclusion of the aneurysmal popliteal segment. The postoperative course required multiple hybrid reinterventions for graft thrombosis and recurrent hemorrhage, including thrombectomy, tibial recanalization, covered stent placement, and embolization. Despite aggressive management, the patient developed refractory bleeding and multi-organ failure, and died in the ICU. Earlier intraoperative tissue sampling might have expedited diagnosis. In young patients with a popliteal aneurysm and atypical course (recurrent hemorrhage or graft failure), routine intraoperative sampling of the aneurysm wall should be considered, to exclude malignancy.