A term neonate presents with tachypnea and mild distress; CXR shows central perihilar markings and mild hyperinflation. What is the likely diagnosis?

• A. Respiratory distress syndrome.
• B. Transient tachypnea of the newborn.
• C. Meconium aspiration.
• D. Pneumonia.

Answer: (B)

Delayed clearance of fetal lung fluid is the main idea here. In a term newborn with tachypnea and mild distress soon after birth, this delayed fluid resorption leads to mild interstitial edema and some air trapping. The chest X-ray pattern of central perihilar markings with mild hyperinflation fits this picture because the fluid is concentrated around the central lanes near the hila and the lungs show subtle overinflation from trapped air. This constellation is classic for transient tachypnea of the newborn and aligns with its typical course: it’s usually self-limited and improves within a day or two with supportive care.

If you compare other conditions, respiratory distress syndrome tends to occur in preterm infants with a diffuse gritty pattern and air bronchograms, rather than predominantly central markings. Meconium aspiration often presents with patchy infiltrates and may be seen in post-term infants, while pneumonia would more often present with focal or diffuse consolidations and sometimes fever.