[1] Kagawa Rosai Hosp, Dept Otolaryngol Head & Neck Surg, Marugame, Kagawa, Japan
[2] Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Dept Otolaryngol Head & Neck Surg, Okayama, Japan
[3] Okayama Univ, Grad Sch Med Dent & Pharmaceut, Dept Pathol, Okayama, Japan
[4] Kagawa Rosai Hosp, Dept Pathol, Marugame, Kagawa, Japan
[5] Int Univ Hlth & Welf, Sch Med, Dept Otolaryngol, Narita, Japan