1. Institute of Pathology, University of Bonn, Bonn, Germany
2. Division of Hematology and Oncology, Department of Internal Medicine III, University of Bonn, Bonn, Germany
3. Institute for Medical Biometry, Computer Science and Epidemiology, University of Bonn, Bonn, Germany
4. Heinz-Werner-Seifert-Institute of Dermatopathology, Bonn, Germany