Ascending retrocecal appendicitis presenting with right upper abdominal pain: utility of computed tomography.

Acute appendicitis is a common surgical condition that is usually managed with early surgery, and is associated with low morbidity and mortality. However, some patients may have atypical symptoms and physical findings that may lead to a delay in diagnosis and increased complications. Atypical presentation may be related to the position of the appendix. Ascending retrocecal appendicitis presenting with right upper abdominal pain may be clinically indistinguishable from acute pathology in the gallbladder, liver, biliary tree, right kidney and right urinary tract. We report a series of four patients with retrocecal appendicitis who presented with acute right upper abdominal pain. The clinical diagnoses at presentation were acute cholecystitis in two patients, pyelonephritis in one, and ureteric colic in one. Ultrasound examination of the abdomen at presentation showed subhepatic collections in two patients and normal findings in the other two. Computed tomography (CT) identified correctly retrocecal appendicitis and inflammation in the retroperitoneum in all cases. In addition, abscesses in the retrocecal space (n = 2) and subhepatic collections (n = 2) were also demonstrated. Emergency appendectomy was performed in two patients, interval appendectomy in one, and hemicolectomy in another. Surgical findings confirmed the presence of appendicitis and its retroperitoneal extensions. Our case series illustrates the usefulness of CT in diagnosing ascending retrocecal appendicitis and its extension, and excluding other inflammatory conditions that mimic appendicitis.