1. Department of Otorhinolaryngology‑Head and Neck Surgery, Keio University School of Medicine, Tokyo 160‑8582, Japan
2. Department of Otorhinolaryngology‑Head and Neck Surgery, International University of Health and Welfare, Narita, Chiba 286‑8582, Japan
3. Department of Otorhinolaryngology‑Head and Neck Surgery, National Hospital Organization Tokyo Medical Center, Tokyo 152‑8902, Japan
4. Department of Otorhinolaryngology‑Head and Neck Surgery, Kawasaki Municipal Kawasaki Hospital, Kawasaki, Kanagawa 210‑0013, Japan
5. Department of Otorhinolaryngology‑Head and Neck Surgery, Saitama City Hospital, Saitama 336‑8522, Japan
6. Department of Pathology, Keio University School of Medicine, Tokyo 160‑8582, Japan