1. 1Department of General Surgery, Clinical Center Kragujevac, Zmaj Jovina 30, 34000, Kragujevac, Serbia
2. 2Department of Pathology, Clinical Center Kragujevac, Zmaj Jovina 30, 34000, Kragujevac, Serbia
3. 3Department of Gastroenterology, Clinical Center Kragujevac, Zmaj Jovina 30, 34000, Kragujevac, Serbia