Interstitial emphysema of the stomach due to perforated appendicitis.

There are three recognised variations of gas within the wall of the stomach (interstitial emphysema, cystic pneumatosis and emphysematous gastritis). Only 26 cases of interstitial emphysema have been described, with an overall mortality of 42%, and we report the first known case of this rare phenomenon associated with acute appendicitis. A description of the clinical and radiological features of these three types of intramural stomach gas is presented and the literature pertinent to interstitial emphysema is reviewed.