Congenital lobar emphysema.
The aetiology of congenital lobar emphysema is not always evident. In the group with demonstrable check-valve mechanism, which allows the air to enter but not to leave the lung, there is either internal stenosis or external compression of the bronchus. When no cause can be found, the condition is called idiopathic, although in some cases alveolar fibrosis has been demonstrated, the check-valve mechanism being in these cases at an alveolar level. In the small group of rare cases of bronchial atresia, air which enters through a collateral ventilation cannot be removed by the same route; in these case too, the check-valve mechanism exists at the alveolar level. Five cases of "congenital lobar emphysema" are presented. One case showed no bronchial anomaly; another case showed an increase in interstitial connective tissue in the lung; tow cases showed hypoplasia or absence of bronchial cartilage; in one case, bronchial atresia was found at operation. Infants show a typical symptomatology of dyspnoea and cyanosis, and a typical chest X-ray with unilateral radiolucency and a delicate lung pattern, collapse of surrounding lung tissue, and mediastinal hernia. In older children, the diagnosis is made either incidently or following a complication. The condition is usually found in the left upper and the right middle lobe. Treatment is surgical and consists of resection of the emphysematous segments.