BACKGROUND: Expansion after popliteal artery aneurysm exclusion with bypass is a common phenomenon. Popliteal angiosarcoma is seldom reported in literature and in most cases after popliteal artery aneurysm surgery. This paper aims to present the case of a popliteal angiosarcoma, initially diagnosed as late aneurysmal growth after exclusion surgery, to conduct a systematic review of popliteal angiosarcoma and assess any association between angiosarcoma and previous popliteal aneurysm surgery. METHODS: We performed a secondary popliteal aneurysmorraphy through posterior approach for symptomatic aneurysm expansion in a 79-year-old woman, 9 years after medial femoropopliteal venous bypass and aneurysm exclusion. The postoperative course was complicated by recurrent hematomas and wound spillages requiring multiple revisions. Pathological analysis identified an angiosarcoma. Staging revealed bone invasion and pulmonary metastasis. Despite transfemoral amputation and adjuvant chemotherapy the patient died 8 months later. We performed a systematic review through MEDLINE on 'primary' and 'secondary' (with previous vascular surgery) angiosarcoma in popliteal artery aneurysm. Research was done using the terms '(hem) angiosarcoma', 'aneurysm', 'popliteal aneurysm or artery', 'femoral aneurysm or artery'. Other soft tissue sarcoma or nonpopliteal locations were excluded. RESULTS: Including this case, only 13 angiosarcomas in popliteal aneurysms are currently described. Two were reported without previous surgery considered as primary angiosarcoma and 11 after popliteal artery aneurysm surgery (secondary angiosarcoma). Patient age ranges from 8 months to 83 years with a male predominance (10/3). Nine of the 11 patients with secondary angiosarcoma were initially diagnosed as popliteal aneurysm expansion after previous bypass surgery, the 2 other secondary cases presented respectively with pain and inflammatory syndrome without expansion. All prior surgical exclusion was carried out by a medial approach. Interval with the index operation ranges from 3 months to 15 years. Death was reported in 8 of the 13 cases within the first year of diagnosis. CONCLUSIONS: Although seldom reported, popliteal angiosarcomas are mainly described after popliteal artery aneurysm exclusion surgery, raising suspicion on a potential association, yet causality cannot be demonstrated. Angiosarcoma should be included in the differential diagnosis of popliteal aneurysm growth or unexpected outcome after exclusion bypass surgery. Systematic imaging and pathological studies should be undertaken to allow early diagnosis and treatment. Routine use of a posterior approach, with aneurysm resection, when feasible as initial popliteal artery aneurysm treatment, might reduce the risk of late sarcomatous transformation.