Acute appendicitis is the most common acute surgical condition of the abdomen. It occurs in patients of all ages, but is most common in the second and third decades. Acute mesenteric adenitis is the disease most often confused with acute appendicitis in children. It is usually associated with a concurrent or recently resolved upper respiratory illness.

The pain of mesenteric adenitis can mimic that caused by appendicitis. Voluntary guarding is common, but. true rigidity is rare. Labwork usually does not help to differentiate between these diseases, but if a relative lymphocytosis is present, it suggests mesenteric adenitis rather than appendicitis.

A careful history is key to making the diagnosis. Since mesenteric adenitis is self-limiting, the patient may improve during close observation by the surgeon. However, if the differentiation remains in doubt, surgical exploration is the safe route.

In light of this diagnostic dilemma, imaging the right lower quadrant is an appealing option to the clinician. The CT findings of mesenteric adenitis consist of several lymph nodes in the right lower quadrant at least 5 mm in the short axis and a normal-appearing appendix.