Angiosarcoma after revision total knee arthroplasty

BackgroundHemarthrosis after total knee arthroplasty (TKA) is a relatively rare complication. Although most cases are effectively treated with conservative therapy, some cases require angiographic embolization or surgical intervention. Angiosarcoma is a rare malignant tumor derived from the vascular endothelium with neovascular hyperplasia and mainly arises in the skin and superficial soft tissue, and less frequently in deep soft tissue and bone. Although malignant neoplasms such as angiosarcoma in the vicinity of orthopedic implants were reported, the causal relationship between development of the malignant tumor and the orthopedic implant is widely debated in the literature.Case presentationWe report the case of a 68-year-old female with angiosarcoma that developed in the knee joint 2 years after revision TKA. The patient exhibited severe persistent bleeding, which reached 1000–1400 ml per day for 4 months. Histological analysis of the synovial tissue in the knee joint showed large cells with nuclear atypia. Immunohistochemical staining showed cells that were positive for CD31, CD34, and D2-40, and she was diagnosed with angiosarcoma. The patient underwent an amputation at the level of the thigh, and her general condition immediately improved after the operation. The patient did not exhibit bleeding from the site of amputation, and no local recurrence or distant metastases were detected 1 year after the amputation.ConclusionsTo the best of our knowledge, this represents the first report of angiosarcoma 2 years after revision TKA. Further careful follow up is needed, given the high-grade malignancy.