1. Department of Pathology and Cytology, Dr. Josip Bencevic General Hospital, Slavonski Brod, Croatia
2. Department of Otorhinolaryngology and Head and Neck Surgery, Dr. Josip Bencevic General Hospital, Slavonski Brod, Croatia
3. Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
4. School of Medicine, University of Belgrade, Belgrade, Serbia
5. Institut of oncology and radiology of Serbia, Belgrade, Serbia