1. University Department of Otorhinolaryngology and Head and Neck Surgery, Ljubljana, Slovenia robert_sifrer@hotmail.com
2. Institute of Oncology Ljubljana, Ljubljana, Slovenia
3. Institute of Pathology, Faculty of Medicine, Ljubljana, Slovenia
4. University Department of Otorhinolaryngology and Head and Neck Surgery, Ljubljana, Slovenia
5. Department of Otorhinolaryngology, General Hospital Novo mesto, Slovenia