[1] European Inst Oncol, Div Endoscopy, Milan, Italy
[2] Univ Hosp Leuven, Dept Gastroenterol, Louvain, Belgium
[3] Poliklin Johannes Guterngerg Univ, Med Klin, Mainz, Germany
[4] Klinikum Bayreuth, Inst Pathol, Bayreuth, Germany
[5] Katholieke Univ Leuven Hosp, Dept Pathol, Louvain, Belgium