1. Institute of Pathology, University Hospital of Cologne, Cologne, Germany
2. Department of Pathology, University Hospital of Muenster, Muenster, Germany
3. Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital of Cologne, Cologne, Germany
4. Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
5. Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital of Muenster, Muenster, Germany