1. Gerhard-Domagk-Institute of Pathology, University Hospital Münster, Münster, Germany
2. Institute of Pathology and Molecular Pathology, Bundeswehrkrankenhaus Ulm, Ulm, Germany
3. Department of Orthopaedics and Tumor Orthopaedics, University Hospital Münster, Münster, Germany
4. Bone Tumor Reference Centre, Institute of Pathology, University Hospital Basel, University of Basel, Basel, Switzerland