Subcutaneous emphysema, pneumomediastinum and pneumoperitoneum after colonoscopy

Colonoscopy is an essential tool to investigate and to manage intraluminal lesions of the colon and has been considered safe although a perforation as a complication of this procedure is often associated with serious morbidity. A 56-year-old woman had a colonoscopic biopsy for a suspicion of colon cancer. After the procedure, the patient complained of neck swelling and abdominal distension and pain. A chest X-ray and abdominal computed tomography scan showed subcutaneous emphysema, pneumomedistinum and pneumoperitoneum. If the colon perforates into the retroperitoneum, air can travel to the mediastinum and subcutaneous tissue as the fascial planes of the cervical soft tissues are in continuity with those of the mediastinum and through the diaphragmatic hiatus with the retorperitoneal soft tissue space. We report here a rare case of ubcutaneous emphysema, pneumomediastinum and pneumoperitoneum that developed after a colonoscopic biopsy.