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

Abstract

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.

Figure 1

A 30-year-old woman presenting with a clinical diagnosis of acute cholecystitis. A and B: Contrast-enhanced computed tomography (CT) sections showing inflammatory changes (arrow) adjacent to the inferior tip of the liver (L); B: Thickened appendix (arrow) with mild inflammatory changes in the retrocecal region; C: Coronal reconstruction showing the extent of inflammatory changes (arrows) from the retrocecal region to the tip of the liver.

Figure 2

A 31-year-old woman presenting with right hypochondrial pain and a clinical diagnosis of pelvic inflammatory disease and right pyelonephritis. A: Contrast-enhanced CT scan showing fluid collection (arrow) in the subhepatic region, extending anteriorly to the gallbladder fossa with inflammatory stranding; B: Note the air fluid level in the collection adjacent to the right kidney; C: Coronal reconstruction showing the long thickened and inflamed appendix (short arrows) reaching the subhepatic region, and the subhepatic collection (arrow) is seen extending more cranially.

Figure 3

A 34-year-old man with colicky right flank pain and clinical diagnosis of right ureteric colic. A: Ultrasound showed a subhepatic fluid collection (arrows) and no other significant abnormality; B: CT scan performed 2 d later showed the collection in the subhepatic region (short arrow). Note the air-fluid level in the anterior collection (long arrow) with inflammatory changes; C: The section at the level of the cecum and appendix shows inflammatory changes in the retrocecal region (short arrow) and thickened appendix (long arrow).

Figure 4

A 27-year-old man with recurrent right upper abdominal pain. A: Ultrasound showed a hypoechoic area in the subphrenic (straight arrow) and subhepatic (broken arrow) region; B: Confirmation by contrast-enhanced CT; C: CT also showed a thickened gallbladder wall (curved arrow), subhepatic collection (white arrow) and inflammation in the perinephric region; D: Another caudal section shows a thickened appendix with inflammatory stranding in the perinephric region.