1. Department of Pathology, Hallym University College of Medicine, Kangnam Sacred Heart Hospital, Seoul, Korea.
2. Department of Pathology, Chung-Ang University College of Medicine, Chung-Ang University Hospital, Seoul, Korea.
3. Department of Otorhinolaryngology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
4. Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.