1. Department of Otorhinolaryngology, Head and Neck Surgery, Ruppiner-Kliniken GmbH, Brandenburg Medical University-Theodor Fontane, Campus Ruppiner Kliniken, Fehrbelliner Straße 38, 16816 Neuruppin, Germany
2. Institute of Pathology, Ruppiner-Kliniken GmbH, Brandenburg Medical University, Campus Ruppiner Kliniken, Fehrbelliner Straße 38, 16816 Neuruppin, Germany
3. Department of Otorhinolaryngology, Head and Neck Surgery, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12200 Berlin, Germany