1. Department of Thyroid and Breast Surgery, Shandong Qianfoshan Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250021, P.R. China
2. Department of Pathology, Jining No.1 People's Hospital, Jining, Shandong 272011, P.R. China
3. Department of Thyroid and Breast Surgery, Jining No.1 People's Hospital, Jining, Shandong 272011, P.R. China