Clinical implication of discrepancies between surgical and pathologic diagnoses of acute appendicitis

Purpose: The postoperative treatment after appendectomy is usually decided on the basis of the surgeons' intraoperative findings. Comparatively, the pathologic diagnosis of appendicitis is confirmed several days after the surgery; therefore, it usually does not affect the postoperative treatment strategy. The aim of this study was to investigate the discrepancies between the surgical and pathologic diagnoses of appendicitis and to identify their clinical implication. Methods: A retrospective observational study was performed in 1,817 patients who underwent 3-port laparoscopic appendectomy for the final diagnosis of appendicitis. The clinical variables that could estimate the severity of appendicitis and the intensity of postoperative treatment were analyzed and compared according to the surgical and pathologic diagnoses. Results: Of 1,321 cases of surgically simple appendicitis, 254 (29.3%) were pathologically complicated appendicitis. On the other hand, 221 of 496 cases (44.5%) of surgically complicated appendicitis were pathologically simple. Neither the surgical nor the pathologic diagnosis of appendicitis affected the development of postoperative intra-abdominal abscess (P = 0.079 for surgical diagnosis; P = 0.288 for pathologic diagnosis); however, the surgical diagnosis showed more correlation with the severity of disease and the intensity of the treatment pathway than did the pathologic diagnosis. Conclusion: There were discrepancies between the surgeons' intraoperative assessment and the pathologists' final histologic diagnosis of appendicitis. The surgeon's classification might be more predictive of the outcome than the pathologist's because only the surgeon's findings are available immediately after surgery.