[1] Philipps Univ Giessen & Marburg, Endoscopy Unit, Dept Internal Med, Div Gastroenterol Endocrinol & Metab, D-35043 Marburg, Germany
[2] Philipps Univ Giessen & Marburg, Inst Pathol, D-35043 Marburg, Germany
[3] Klinikum Bayreuth, Inst Pathol, Bayreuth, Germany
[4] Philipps Univ Giessen & Marburg, Dept Surg, D-35043 Marburg, Germany