1. Department of Surgery, Kuma Hospital, Hyogo 650-0011, Japan
2. Thyroid Center, Showa University Northern Yokohama Hospital, Kanagawa 224-8503, Japan
3. Department of Endocrinology, Noguchi Thyroid Clinic and Hospital Foundation, Oita 874-0902, Japan
4. Department of Internal Medicine, Ito Hospital, Tokyo 150-8308, Japan
5. Department of Thyroid and Endocrinology, Fukushima Medical University School of Medicine, Fukushima 960-1295, Japan
6. Department of Endocrinology and Metabolism Center, IMS Miyoshi General Hospital, Saitama 354-0041, Japan