1. Department of Otolaryngology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, P.R. China
2. Department of Otolaryngology, People’s Hospital of Haining City, Haining, Zhejiang, P.R. China
3. Department of pathology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, P.R. China