When is a pneumothorax not a pneumothorax?

The authors report on a 13-year-old boy who, after exercise, had respiratory distress and left upper quadrant abdominal pain. Initially, a mistaken diagnosis of pneumothorax was made, and a chest tube was inserted. A nasogastric tube was then visualized on chest x-ray in the left hemithorax. He underwent a laparotomy and had herniation of spleen, stomach, and large and small bowel in the left pleural space passing through a traumatic defect in the hemidiaphragm. The laparoscopic Nissen fundoplication 3 years prior was felt to have contributed. A timely and correct diagnosis is essential to avoid the sequelae associated with these injuries and with inappropriate tube thoracostomy.