1. Department of Otorhinolaryngology, Head and Neck Surgery Nagoya City University Graduate School of Medical Sciences Nagoya Japan
2. Department of Pathology and Molecular Diagnosis Nagoya City University Graduate School of Medical Sciences Nagoya Japan
3. Department of Anatomic Pathology Tokyo Medical University Tokyo Japan
4. Department of Head and Neck Oncology and Surgery, Mita Hospital International University of Health and Welfare Tokyo Japan
5. Department of Head and Neck, Esophageal Medical Oncology National Cancer Center Hospital Tokyo Japan
6. Department of Otolaryngology–Head and Neck Surgery Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama Japan