New Insights: P.I.G in Preterm Infants With Isolated PDA and Severe Pulmonary Hypertension.

We present a case of a premature infant who had a persistent patent ductus arteriosus (PDA) and subsequently developed severe pulmonary hypertension (PHT) and respiratory failure. A lung biopsy was performed during PDA ligation, revealing a consistent thickening of the interstitial tissue. The biopsy also showed the presence of immature interstitial cells containing high amounts of cytoplasmic glycogen, indicative of pulmonary interstitial glycogenosis (P.I.G). There was no conclusive evidence of maturational arrest, infection, alveolar proteinosis, or alveolar capillary dysplasia. While the association between P.I.G and PHT has been documented in case reports involving children with congenital heart disease (CHD), the majority of these cases involved full-term infants and older children. Notably, there have been no reports on the diagnosis of P.I.G in infants with isolated PDA, without any other congenital heart conditions. This expands the existing knowledge of P.I.G, highlighting the diagnostic value of lung biopsy in premature infants with long-standing PDA and severe PHT exhibiting similar characteristics.