Capillary alveolar dysplasia is often initially misdiagnosed in the neonatal period as which congenital lung lesion?

• A. Congenital adenomatoid malformation
• B. Persistent pulmonary hypertension of the newborn
• C. Respiratory distress syndrome
• D. Bronchopulmonary dysplasia

Answer: (A)

Capillary alveolar dysplasia often presents in the newborn with severe, refractory pulmonary hypertension and respiratory distress, and its imaging can resemble a congenital cystic lung lesion. Because congenital adenomatoid malformation (CAM, a CPAM) is a well-known congenital lung lesion that appears as a cystic mass in neonates, clinicians frequently label CAB as CAM in the early neonatal period. Only later, often on autopsy or with histology showing misaligned capillaries and alveolar-capillary dysplasia, is the true diagnosis confirmed. The other options reflect different conditions or categories (PPHN as a syndrome, RDS as surfactant deficiency, BPD as chronic lung disease), not distinct congenital lung masses, so they don’t fit the misdiagnosis pattern as well.