1. Department of Otorhinolaryngology–Head and Neck Surgery, Osaka University Graduate School of Medicine, Suita City, Osaka, Japan
2. Department of Pathology, Osaka University Graduate School of Medicine, Suita City, Osaka, Japan
3. Department of Otorhinolaryngology, Hyogo Prefectural Nishinomiya Hospital, Nishinomiya City, Hyogo, Japan