Subcutaneous emphysema of the lower extremity of gastrointestinal origin.

Two cases of subcutaneous emphysema of the left lower extremity secondary to perforations of the rectum ,nd sigmoid colon are presented. Although this is an extremely rare syndrome, the true incidence is probably higher, as some cases will be misdiagnosed as gas gangrene unless careful clinical and postmortem examinations are performed. Only rapid recognition of the probable origin of the gas, coupled with aggressive, definitive therapy, can prevent the usually fatal course of this condition. In the absence of trauma to the chest or infection in a previously normal leg, subcutaneous emphysema of a limb should alert the physician to the possibility of a gastrointestinal perforation as a source of the gas. Perforations of the gastrointestinal tract into the subcutaneous tissue can occur anywhere from the neck to the lower extremities.