1. 2nd Academic ORL, Head and Neck Surgery Department, Aristotle University of Thessaloniki, Papageorgiou Hospital, Thessaloniki, Greece
2. Department of Pathology, “Theageneion” Cancer Hospital, Thessaloniki, Greece
3. Department of Otorhinolaryngology, Head and Neck Surgery, Faculty of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece
4. Department of Otorhinolaryngology-Head and Neck Surgery, “G. Papanikolaou” General Hospital, Thessaloniki, Greece