Unusual histopathological findings in appendectomy specimens with clinical diagnosis of acute appendicitis: A retrospective cohort analysis

Introduction: While appendicitis is considered one of most common acute surgical conditions, several studies have reported abnormal histopathological findings in appendectomy specimens; however, sending all appendices to histopathology is not yet routinely done.Here we report many unusual findings. Those unusual findings played a role not only in confirming acute appendicitis as a cause of the presentation in some cases but also discovering etiologies that mimic it with great impact on its management. Methods: Between January 2011 and December 2017, a total of 1510 patients were operated with appendectomy for a primary diagnosis of acute appendicitis. Among them, a total of 72 patients had incidental histopathologic findings in association with acute appendicitis or other pathologies instead of acute appendicitis. A retrospective analysis for those 72 patients was performed with all data being retrieved from the electronic health record system. Results: Patients ages ranged between 4 and 71 years with a mean age equal to 23.1 years (SD = 14.2). Majority of patients were women (n = 52; 72.2%). Sixty of the seventy-two cases were seen in patients with negative appendectomies (n = 333) with an overall rate of 18% among this group of patients. The remaining 12 patients had additional findings in histopathology specimens beside acute appendicitis (n = 1131) with an overall rate of 1%. The most commonly reported pathologies were serositis, ovarian cysts, and Enterobius vermicularis in descending frequency. Conclusion: Identification of unusual histopathological findings during microscopic examination of resected appendices is more common in female patients and in patients with negative appendectomy. histopathologic assessment of specimens will allow detection of congenital, infectious or malignant pathologies that mimic acute appendicitis clinically even in the absence appendicitis microscopically.