Case Report: Primary epithelioid angiosarcoma of the femur: two rare cases with atypical skeletal involvement

Abstract

Background Primary epithelioid angiosarcoma (EA) is an exceptionally rare malignant vascular tumor with aggressive behavior and nonspecific imaging features. Femoral involvement is particularly uncommon and may mimic other destructive bone neoplasms. Case report We describe two men with primary EA of the femur. One patient presented with progressive right hip pain and a pathological fracture of the proximal femur, whereas the other presented with progressively worsening pain in the distal left thigh. Imaging demonstrated destructive osteolytic lesions with intramedullary involvement and variable extension into the adjacent soft tissues. Both patients underwent wide tumor resection followed by prosthetic reconstruction. Histopathological examination revealed malignant epithelioid vascular neoplasms, and immunohistochemical (IHC) positivity for endothelial markers supported the diagnosis. Conclusion Primary femoral EA should be considered in the differential diagnosis of aggressive osteolytic lesions, particularly when relatively limited enhancement, hemorrhagic components, and adjacent soft tissue extension are present. Definitive diagnosis requires integrated assessment of radiological, histopathological, and IHC findings.