1 Medical Intern, Faculty of Medicine, School of Medicine, Shahrood Branch, Islamic Azad University, Shahrood, Semnan, Iran a Emial Address: [email protected] Student Research Committee, Shahrood Branch, Islamic Azad University, Shahrood, Iran b Email Address: [email protected] Student Research Committee, Shahrood Branch, Islamic Azad University, Shahrood, Iran c Email Address: [email protected]: Hessamedin Babaei Email: [email protected] Clinical MassageAcute appendicitis remains one of the most frequent cause of emergent abdominal operations, diagnosed by combination of history, examination, and investigations to build a full clinical picture. The 63-year-old female presented in this case has had right lower quadrant abdominal pain for 10 days before the presentation. Her history, examination, and laboratory results didn’t support a diagnosis of acute appendicitis. Ultrasonography identified acute perforated appendicitis with minimal fluid collection, which led to her hospital admission. Subsequent laboratory investigations became consistent over time and patient prepared for the appendectomy. This case focuses on a rare presentation of a common disease. It seeks to point out the significance of using para-clinical tests judiciously in conjunction with clinical findings.Keywords: Appendicitis,INTRODUCTIONAcute appendicitis remains one of the most frequent cause of emergent abdominal operations with a lifetime risk of 8.6% in males and 6.7% in females1,2. Although in most cases this is an easily reached diagnosis, presentation is not always typical and there are certain other conditions which may mimic appendicitis. In fact the classical presentations only occur in 50% of cases2. Anatomical variations of the appendix and timing of presentation can make the clinical picture more cumbersome3. While there may be instances where operating on a patient without prior imaging examination is deemed appropriate, this should be regarded as an exception rather than a rule. The liberal utilization of imaging techniques to enhance preoperative diagnostic accuracy and minimize the incidence of negative appendectomy is an ongoing trend that is expected to persist4,5. The goal of treatment is preventing the condition to reach its potentially serious complications, including perforated and gangrenous appendicitis, abscess formation, intestinal obstruction, septic seeding of mesenteric vessels6.