1. Department of Gastroenterology, Digestive Diseases and Intensive Care Medicine (Department of Medicine III), University Hospital RWTH Aachen, Aachen, Germany
2. Department of General, Visceral and Transplantation Surgery, University Hospital RWTH Aachen, Aachen, Germany
3. Department of Nuclear Medicine, University Hospital RWTH Aachen, Aachen, Germany
4. Institute of Pathology, University Hospital RWTH Aachen, Aachen, Germany
5. Institute of Pathology, Hannover Medical School, Hannover, Germany