Congenital Appendiceal Atresia: An Extremely Rare Disorder Presenting with Acute Abdomen

Abstract Introduction/Objective Congenital malformations of the appendix are extremely rare and difficult to diagnose preoperatively. One of those anomalies include congenital appendiceal atresia (CAA) which mimics acute appendicitis and is usually ignored in the differentials of acute abdomen. Herein, we present a case study of congenital appendiceal atresia associated with periappendicitis. Methods/Case Report A 62-year-old female with past history of diverticulitis presented with complaints of crampy, diffuse and progressive lower abdominal pain and nausea for two days. She denied fevers, chills or change in bowel movements. Physical examination revealed vitally stable patient with soft, non-distended and tender abdomen in bilateral lower quadrants, worse on the right side and showing positive rebound test. Her complete blood count and chemistry were within normal limits. A computerized tomography arterial portography (CTAP) scan with contrast demonstrated inflammatory stranding around the appendix without abscess, concerning for acute appendicitis. She then underwent laparoscopic appendectomy. Grossly, the appendix consisted of a cylindrical portion of yellow-pink fatty tissue covered by peritoneum measuring 6.2 x 3.3 x 0.5 cm. The peritoneal surface displayed patchy fibrinous exudates. Sectioning revealed yellow adipose tissue with no identifiable appendix. Microscopically, the entire specimen demonstrated a poorly formed, mainly fatty appendix without a discernible lumen or submucosal lymphoid tissue. There were scattered sparsely distributed non-continuous bundles of smooth muscle (muscularis propria) at the periphery, which were highlighted by desmin and trichrome stains. This atretic appendix, mesoappendix and peritoneal covering were acutely inflamed. The final diagnosis was poorly formed, acutely inflamed fatty appendix consistent with congenital appendiceal atresia with accompanying acute periappendicitis. Results (if a Case Study enter NA) NA Conclusion This case would add to the very limited existing literature for congenital appendiceal anomalies and highlight the importance of thorough surgical intraoperative abdominal exploration and submission of the entire specimen for microscopic examination in order to render a definitive diagnosis.