1. Department of Orthopaedic Surgery, Muenster University Hospital, Muenster, Germany
2. Institute of Pathology, Starnberg, Germany
3. Department of Pediatrics, Olga Hospital, Stuttgart, Germany; University Children's Hospital, Paediatric Haematology and Oncology, University of Muenster, Muenster, Germany
4. Department of Radiology, Muenster University Hospital Muenster, Germany
5. University Children's Hospital, Paediatric Haematology and Oncology, University of Muenster, Muenster, Germany
6. Institute of Pathology, Muenster University Hospital Muenster, Germany
7. Institute of Pathology, Muenster University Hospital, University of Muenster, Domagkstr.17, 48149 Muenster, Germany;