1. Department of Internal Medicine; Chung-Ang University Hospital; Chung-Ang University College of Medicine; Dongjak-gu Seoul Korea
2. Department of Pathology; Dongnam Institute of Radiological & Medical Sciences; Gijang-gun Busan Korea
3. Department of Internal Medicine; Korea Cancer Center Hospital; Nowon-gu Seoul Korea
4. Department of Pathology; Korea Cancer Center Hospital; Nowon-gu Seoul Korea
5. Otolaryngology-Head and Neck Surgery; Korea Cancer Center Hospital; Nowon-gu Seoul Korea
6. Department of Pathology; Seoul National University Boramae Medical Center; Dongjak-gu Seoul Korea
7. Department of Internal Medicine; Seoul National University Boramae Medical Center; Dongjak-gu Seoul Korea
8. Department of Internal Medicine; Seoul National University College of Medicine; Chongno-gu Seoul Korea