1. Department of Digestive Endoscopy, Tokyo Women’s Medical University Hospital, 8-1 Kawada-Cho, Shinjuku-Ku, Tokyo 162-8666, Japan
2. Department of Surgical Pathology, Tokyo Women’s Medical University Hospital, 8-1 Kawada-Cho, Shinjuku-Ku, Tokyo 162-8666, Japan
3. Division of Gastroenterology, Tokyo Women’s Medical University Hospital, 8-1 Kawada-Cho, Shinjuku-Ku, Tokyo 162-8666, Japan