1. Department of Oncology-Pathology, Karolinska Institute, CCK, Stockholm, Sweden;
2. Department of Clinical Pathology, Cancer Center Karolinska, Karolinska Institute, Stockholm, Sweden;
3. Department of Pathology, Haartman Institute and HusLab, Helsinki University Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland;
4. Department of Otorhinolaryngology – Head and Neck Surgery, University of Helsinki and Helsinki University Hospital, Helsinki, Finland;
5. Division of Ear, Nose and Throat Diseases, Department of Clinical Sciences, Intervention and Technology, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden