1Department of Surgery, Rogaland Central Hospital, Armauer Hansensvei 20, P.O. Box 8100, N-4003 Stavanger, Norway.
2Department of Surgery, Rogaland Central Hospital, Armauer Hansensvei 20, P.O. Box 8100, N-4003 Stavanger, Norway, , NO
3Department of Pathology, Rogaland Central Hospital, Armauer Hansensvei 20, P.O. Box 8100, N-4003 Stavanger, Norway, , NO