2018 Volume 33 Issue 4 Pages 609-613
An 82-year-old woman had regularly seen a doctor for treatment of diabetes mellitus, bronchial asthma, hypertension and angina pectoris. Acarbose had been prescribed for her diabetes mellitus. Since February 2016, loose stools had continued and she underwent a fecal occult blood test, which was positive. Total colonoscopy was performed, and multiple smooth submucosal tumors were detected in the sigmoid colon, which were partially reddish, and had attached clots. These lesions appeared as multiple emphysematous cysts along the colon wall on CT colonography and pneumatosis cystoides intestinalis was diagnosed. As symptoms were mild and blood glucose control was good, administration of acarbose was continued carefully. As the loose stools continued, they were probably due to acarbose, which was stopped. One month later, colonoscopy revealed improvement in the cystoid lesions of the sigmoid colon and therefore the pneumatosis cystoides intestinalis in this case was thought to be an adverse effect of acarbose.
Pneumatosis cystoides intestinalis appears as submucosal or subserosal emphysematous cysts, which sometimes result in a positive fecal occult blood test. As cases of pneumatosis cystoides intestinalis occurring as a complication of colon cancer have been reported, care is needed. Rupture of subserosal cysts results in intraperitoneal free air, but rarely requires surgery. When intraperitoneal free air is detected in an imaging study, a calm response in view of organic solvent usage history, present illness, medication taken, symptoms and abdominal examination findings should be made. Medical staff engaged in general checkups need to keep pneumatosis cystoides intestinalis in mind.