1. Department of Otorhinolaryngology, Head and Neck Surgery; University Hospital of Zurich, University of Zurich; Zurich Switzerland
2. Department of Pathology and Molecular Pathology; University Hospital of Zurich, University of Zurich; Zurich Switzerland
3. University Hospital of Zurich, University of Zurich; Zurich Switzerland
4. Institute of Pathology, Kantonsspital Graubuenden; Chur Switzerland
5. Department of Otorhinolaryngology, Head and Neck Surgery; Kantonsspital St. Gallen; St. Gallen Switzerland