Differentiating appendiceal neoplasm from perforated appendiceal diverticulum in chronic appendicitis: a case report

Low mucinous neoplasm of the appendix (LAMN) and appendiceal diverticulum are both uncommon pathologies that may pose a diagnostic challenge. Both may present as either appendicitis or asymptomatically and have a risk of perforation. LAMN, carries the additional risk of pseudomyxoma pertitonei and metastasis. Ensuring correct histopathology is crucial, as computed tomography (CT) abdomen/pelvis may only demonstrate a mildly dilated appendix, delaying diagnostic laparoscopy and appendicectomy. Here, we describe the case report of a 56-year-old woman who presented with chronic intermittent right iliac fossa pain initially determined to be chronic appendicitis. Following laparoscopic appendicectomy, histopathology demonstrated LAMN, however, on further re- assessment of histopathology, as well as the completion of a normal pan-CT and colonoscopy, a final diagnosis of ruptured appendiceal diverticulum was made. Our case demonstrates the utility of a multi-disciplinary approach in evaluating patients with possible appendiceal LAMN or appendiceal diverticulum.