1. Department of General, Visceral and Transplantation Surgery, Division of Plastic, Reconstructive and Hand SurgeryUniversity Hospital Essen, University Essen‐Duisburg Germany
2. Department of Medical Oncology, Sarcoma Center, West German Cancer CenterUniversity Hospital Essen, University of Duisburg‐Essen Germany
3. Institute of Pathology and Neuropathology, University Hospital of EssenUniversity of Duisburg‐Essen Germany
4. Department of Tumor Orthopedics and Sarcoma SurgeryUniversity Hospital Essen, University Essen‐Duisburg Germany