1. Department of Otorhinolaryngology, Head and Neck Surgery; Kantonsspital St. Gallen; St. Gallen Switzerland
2. Clinical Trials Unit; Kantonsspital St. Gallen; St. Gallen Switzerland
3. Department of Otorhinolaryngology, Head and Neck Surgery; University Hospital of Lausanne; Lausanne Switzerland
4. Department of Pathology; University Hospital of Lausanne; Lausanne Switzerland
5. Department of Otorhinolaryngology, Head and Neck Surgery; University Hospital of Zurich; Switzerland
6. Institute of Surgical Pathology; University Hospital of Zurich; Zurich Switzerland
7. Department of Otorhinolaryngology, Head and Neck Surgery; Bern University Hospital; Inselspital Switzerland
8. Department of Pathology; Bern University Hospital; Inselspital Switzerland
9. Department of Otorhinolaryngology, Head and Neck Surgery; Kantonsspital Aarau; Switzerland
10. Department of Pathology; Kantonsspital Aarau; Switzerland
11. Department of Otorhinolaryngology, Head and Neck Surgery; Kantonsspital Fribourg; Switzerland
12. Institute of Pathology; Promed SA; Fribourg Switzerland
13. Oncology Institute of Southern Switzerland (IOSI); Bellinzona Switzerland
14. Department of Radiooncology; Oncology Institute of Southern Switzerland (IOSI); Bellinzona Switzerland
15. Institute of Pathology; Kantonsspital St. Gallen; Switzerland