Localized persistent interstitial pulmonary emphysema presenting as a spontaneous tension pneumothorax in a full term infant.

Persistent interstitial pulmonary emphysema (PIPE) is a syndrome characterized by air-leakage in the perivascular tissues of the lung, primarily affecting mechanically ventilated neonates. Reports in the literature of infants developing PIPE with no history of respiratory distress syndrome (RDS) or mechanical ventilation are scarce. Here, we present a case of a 3-month-old former full term male infant with no history of RDS or mechanical ventilation who presented with focal cystic lung disease associated with spontaneous tension pneumothorax. He was ultimately found to have PIPE based on pathologic evaluation of the resected cystic region. We believe that focal PIPE should be included in the differential diagnosis of cystic lung disease in a full term, unventilated infant, even when spontaneous pneumothorax is the presenting entity.