CT evaluation of a perforated appendicitis.

Clinical History

A 48 year-old woman with an acute appendicitis.

Imaging Findings

A 48 year-old woman was admitted in the emergency department of our hospital for an acute abdominal pain. She underwent a contrast-enhanced CT scan (CECT) which showed a disomogeneous mass, fluid pool, air bubbles and calcified stones inside of it , located in right lower quadrant involving the mesentery and the abdominal wall; ileum and cecum wall thickening as well as free abdominal effusion and mesenteric lymphadenopathy were demonstrated. A perforated appendicitis with appendicoliths, periappendiceal abscess and inflammation involving the bowel wall and the surrounding soft tissues was diagnosed . Surgery was then performed and the imaging results were confirmed.

Discussion

Appendicitis is the most common cause of acute abdominal pain. Patients may present a wide variety of clinical manifestations, and the diagnosis may elude even the most experienced clinicians. Acute appendicitis may occur at any age; abdominal CECT is a well-established technique in the study of patients with acute abdominal pain and has shown high sensitivity (88-100%) and specificity (91-99%) in evaluating complicated inflammatory disease, useful in detecting the inflammed appendix, the involved surrounding tissues, helpful in differentiating appendicitis from other pathological conditions. CT findings in acute appendicitis are usually represented by a dilated non-compressible appendix with circumferential and symmetric wall thickening (7-15mm diameter). The thickened wall usually is homogeneously enhanced, although mural stratification with a target pattern may be noted. We can also observe periappendiceal inflammation, present in 98% of cases, and appendicolith, (hard, noncrushable, calcified stones), tipically present in perforated appendicitis and in periappendiceal abscess. Cecal apical thickening could be observed. Inflammatory signs include periappendiceal fat stranding, thickening of the lateral conal fascia and mesoappendix, extraluminal fluid, phlegmon, abscess, ileocecal mild lymphnode enlargement. Appendiceal perforation is one of the major complications in acute appendicitis. Phlegmon, (described as an ill-defined periappendiceal inflammation), abscess ( a localized fluid collection with wall enhancement with or without interior air component), and extraluminal air in the right lower quadrant , are the direct signs for diagnosing perforated appendicitis. Appendicoliths are significantly more frequent in perforated appendicitis than in appendicitis with no perforation. Peritonitis, bowel obstruction, septic seeding of mesenteric vessels and gangrenous appendicitis, could represent other complications that may occur in acute appendicitis.

Differential Diagnosis List

Final Diagnosis

Acute appendicitis complicated with periappendiceal abscess and perforation.

URL:	https://www.eurorad.org/case/5649
DOI:	10.1594/EURORAD/CASE.5649
ISSN:	1563-4086