1. Department of Otolaryngology Head and Neck Surgery, Technical University of Munich, Muenchen, Germany
2. Department of Otolaryngology Head and Neck Surgery, Section of Phoniatrics and Pedaudiology, University of Ulm, Ulm, Germany
3. Institute of Pathology, Julius-Maximilians-University and Comprehensive Cancer Center Mainfranken, Wuerzburg, Germany
4. Department of Gynecology and Obstetrics; University of Regensburg, Regensburg, Germany