1. Department of Medicine Huddinge, Karolinska Institute, Stockholm, Sweden
2. Department of Upper Abdominal Diseases, Karolinska University Hospital, Stockholm, Sweden
3. Department of Surgery, Endoscopy Unit, Linköping University Hospital, Linköping, Sweden
4. Department of Pathology and Cytology, Linköping University Hospital, Linköping, Sweden
5. Department of Surgery, Örebro University Hospital, Örebro, Sweden