Capillary alveolar dysplasia is often initially diagnosed as which of the following conditions?

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

Answer: (B)

Capillary alveolar dysplasia presents with severe neonatal respiratory failure and marked pulmonary hypertension due to abnormal development of the pulmonary capillary network. This combination produces profound hypoxemia and high pulmonary vascular resistance that closely resembles persistent pulmonary hypertension of the newborn, so clinicians often initially diagnose PPHN. The key distinction is that CAD’s hypertension is due to structural capillary abnormalities, and the diagnosis is typically confirmed later by lung biopsy showing misaligned pulmonary veins and a reduced or disorganized capillary bed, along with a poor or atypical response to standard PPHN therapies. The other conditions fit different contexts: respiratory distress syndrome is common in preterm infants due to surfactant deficiency, bronchopulmonary dysplasia develops after prolonged oxygen/ventilation in preterms, and a congenital adenomatoid malformation is a separate congenital lung lesion with a distinct imaging appearance.