A chest radiograph showing hyperinflation with perihilar and interstitial streaky infiltrates in a neonate most strongly suggests which diagnosis?

• A. Meconium aspiration syndrome
• B. Persistent pulmonary hypertension of the newborn
• C. Transient tachypnea of the newborn
• D. Pulmonary edema

Answer: (C)

This radiographic pattern is most characteristic of transient tachypnea of the newborn. The lungs are hyperinflated from air trapping after birth because fetal lung fluid clearance is delayed, especially after cesarean delivery. The prominent perihilar streaky interstitial markings reflect interstitial fluid, which is typical in TTN, and the heart size is usually normal.

Meconium aspiration, by contrast, often shows patchy heterogeneous infiltrates or areas of atelectasis rather than uniform perihilar interstitial markings. Persistent pulmonary hypertension of the newborn tends to show different patterns with more prominent vascular markings and issues related to right-to-left shunting, and pulmonary edema usually presents with interstitial and alveolar edema plus possible cardiomegaly. Therefore the described radiographic findings point most strongly to transient tachypnea of the newborn.