1. Clinic I of Internal Medicine, GHSG, Supported in Part by the Competence Network Malignant Lymphoma, University of Cologne, Cologne, Germany
2. Dept. of Radiotherapy, University Hospital Cologne, Cologne, Germany
3. Dept. of Oncology, Kantonsspital Basel, Basel, Switzerland
4. Medical Clinic of Hematology and Oncology, University Hospital of Berlin, Berlin, Germany
5. Medical Clinic II, University of Tuebingen, Tuebingen, Germany
6. Medical Clinic III, University of Innsbruck, Innsbruck, Austria
7. Dept. of Hematology, University Hospital of Prague, Prague, Czech Republic
8. Dept. of Pathology, University of Wuerzburg, Wuerzburg, Germany