Thoracic stab wound with delayed pneumoperitoneum and pneumomediastinum.

A 21-year-old man with an innocent-appearing, self-inflicted stab wound to the left upper anterior chest developed pneumoperitoneum and pneumomediastinum seven hours after the injury. At laparotomy he had lacerations of the left hemidiaphragm and anterior wall of the stomach, which were surgically repaired. He recovered without complications. Although brief (four- to six-hour) outpatient observation of patients with seemingly superficial thoracic stab wounds recently has been recommended, this case suggests that longer observation periods for such injuries may be appropriate.