1. Department of Otolaryngology‑Head and Neck Surgery, Wakayama Medical University, Wakayama, Wakayama 641‑8509, Japan
2. Department of Pathology, Wakayama Medical University, Wakayama, Wakayama 641‑8509, Japan
3. Noguchi Thyroid Clinic and Hospital Foundation, Beppu, Oita 874‑0902, Japan