Affiliation: | 1. Department of Otorhinolaryngology‐Head and Neck Surgery, Oslo University Hospital, Rikshospitalet, Oslo, Norway;2. Department of Otorhinolaryngology‐Head and Neck Surgery, Akershus University Hospital, N‐1370 Nordbyhagen, Norway;3. Division of Pathology and Institute of Pathology, Oslo University Hospital, Rikshospitalet, N‐0027 Oslo, Norway |