1. Department of Education, Chang Gung Memorial Hospital, Linkou, Taiwan
2. School of Medicine, Chang Gung University, Taoyuan, Taiwan
3. Department of Pathology, Chang Gung Memorial Hospital, Linkou, Taiwan
4. Institute of Pathology, University of Würzburg, Würzburg, Germany
5. Division of Otology, Department of Otolaryngology–Head and Neck Surgery, Chang Gung Memorial Hospital, Linkou, Taiwan