. At the study hospital, all macroscopically normal appendices are invariably removed for histological examination if no other significant pathology is found during the operation. The operative procedures were therefore in all cases, where appendicitis was preoperatively suspected, registered as appendectomies - not as diagnostic laparoscopies. For the study, complicated appendicitis was defined as perforated appendix or appendicular abscess. Three patients with appendicular abscess were initially treated non-operatively and thus did not have histopathological diagnosis. They were classified as acute appendicitis based on CT findings.