Pulmonary lobar interstitial emphysema.

Pulmonary interstitial emphysema is a relatively common entity in neonatal intensive care units. It can occur in full-term babies but more frequently occurs in premature infants receiving positive pressure ventilation. The process can be localized or diffuse, and the diagnosis is based on the presence of air in the interstitial pulmonary tissue, observed by radiology. The localized form is more rare and one or more lobes may be involved in the process. Our case report is of a second twin male, born after 33 weeks of gestation. After birth, a mild respiratory distress was installed, and the patient was treated with nasal continuous positive airway pressure. After two pneumothoraces, an image of diffuse cystic changes was observed in the right upper lobe. The patient was operated with the clinical and radiologic diagnosis of cystic adenomatoid malformation. The histological study of the resected lobe, by light and scanning electron microscopy, revealed a localized pulmonary interstitial emphysema.