1. Department of Internal Medicine (Division of Endocrinology), Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea.
2. Thyroid Center, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea.
3. Department of Surgery, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea.
4. Department of Pathology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea.