1. Department of Internal Medicine A, University Medicine Greifswald, 17475 Greifswald, Germany
2. Gastroenterology-Endoscopy Center, Hue University of Medicine and Pharmacy, Hue University, Hue 49000, Vietnam
3. Faculty of Medicine and Pharmacy, Tay Nguyen University, 567 Le Duan Street, Buon Ma Thuot 63000, Vietnam
4. Department of Histology, Embryology, Pathology and Forensic, University of Medicine and Pharmacy, Hue University, 6 Ngo Quyen Street, Hue 49000, Vietnam
5. Faculty of Basic Science, University of Medicine and Pharmacy, Hue University, 6 Ngo Quyen Street, Hue 49000, Vietnam
6. Department of Pathology, Khanh Hoa Oncology Hospital, 229 Nguyen Khuyen Street, Nha Trang 57000, Vietnam