1. Division of Pulmonary Medicine, Department of Internal Medicine, Saiseikai Utsunomiya Hospital, Japan
2. Division of Hematology, Department of Internal Medicine, Saiseikai Utsunomiya Hospital, Japan
3. Department of Otorhinolaryngology, Head & Neck Surgery, Saiseikai Utsunomiya Hospital, Japan
4. Department of General Thoracic Surgery, Saiseikai Utsunomiya Hospital, Japan
5. Department of Pathology, Keio University School of Medicine, Japan