Methicillin Resistant Staphylococcus Aureus Colonization, The Tip of the Iceberg for Congenital Pulmonary Airway...

Congenital Pulmonary Airway Malformation (CPAM) is a rare congenital anomaly of the lung that is infrequently diagnosed in the neonatal period, especially in preterm infants without prenatal detection. Methicillin-Resistant Staphylococcus aureus (MRSA) colonization and infection in preterm neonates can further complicate diagnosis and clinical progression.

To describe a rare presentation of CPAM diagnosed in a preterm neonate following late-onset MRSA sepsis, emphasizing the diagnostic challenge and the interplay between infection and congenital malformation.

We present a case report of a preterm female infant (28+3 weeks gestational age, birth weight 1100g), the second of twins, with an initially unremarkable postnatal chest X-ray. She developed clinical deterioration on day 17 of life, and investigations revealed MRSA colo-nization and positive tracheal aspirate cultures. Progressive radiological changes led to further imaging and diagnosis of CPAM. A systematic literature review was also conducted to identify similar cases of CPAM in preterm neonates.

Initial imaging showed no signs of pulmonary malformation. However, after the onset of MRSA-related late-onset sepsis (LOS), follow-up imaging revealed a multiloculated cystic lesion in the right upper lobe. A CT scan confirmed a differential diagnosis of CPAM type II versus necrotizing pneumonia. Surgical lobectomy was performed on day 40 of life, and histopathology confirmed CPAM type I with focal mucinous metaplasia. Postoperative recovery was successful, and the infant was discharged home in stable condition on day 90 of life.

This case highlights the possibility that MRSA sepsis may serve as a trigger or unmasking event for underlying CPAM in preterm neonates. The absence of antenatal diagnosis and delayed radiological changes in this case emphasize the need for a high index of suspicion in the setting of localized pulmonary pathology during systemic infection. In reviewing the literature, this represents one of the few documented cases of CPAM in a preterm neonate without prenatal suspicion. Prompt recognition and multidisciplinary management are essential for optimizing outcomes in such complex cases.