1. Department of Surgery, Erasmus University Medical Center Rotterdam, Rotterdam, the Netherlands
2. Department of Pathology, Free University Medical Center, Amsterdam, the Netherlands
3. Department of Surgery, Jeroen Bosch Hospitals, Hertogenbosch, the Netherlands
4. Department of Surgery, University Medical Center Utrecht, Utrecht, the Netherlands
5. Department of Surgery, IJsselland Hospital, Capelle aan den IJssel, the Netherlands
6. Department of Surgery, Havenziekenhuis, Rotterdam, the Netherlands