A Case of Pneumatosis Cystoides Intestinalis with Free Air Mimicking Perforated Diffuse Peritonitis

Abstract A 69-year-old man was admitted to the emergency medical center of our hospital in September 2008, with complaints of abdominal pain and distension. Clinical examination showed abdominal distension, decreased bowel sounds, and tenderness in the right upper abdomen with rebound tenderness. Unenhanced abdominal computed tomography showed intra-abdominal free air, ascites, and air collection within the bowel wall. The possibility of perforated peritonitis associated with the unexplained free air and ascitic fluid could not be eliminated, and therefore, emergency laparotomy was performed. During the surgery, a large amount of free air escaped when the abdomen was opened. Multiple gas-filled subserosal vesicles were found to be scattered throughout the surface of the bowel wall and the mesentery and almost entirely in the small intestine. There was no evidence suggestive of gastrointestinal tract perforation. Therefore, pneumatosis cystoides intestinalis (PCI) was diagnosed. After the surgery, the patient has remained healthy, and no recurrence of PCI has been observed to date.