If a bronchopulmonary sequestration is large, it can present as respiratory insufficiency due to which mechanisms?

• A. Pulmonary hypoplasia
• B. Lung compression
• C. Both A and B
• D. Neither A nor B

Answer: (C)

A large bronchopulmonary sequestration can cause respiratory distress because it acts as a space-occupying mass within the chest, affecting both development and ventilation of the lung. First, during fetal growth, a sizable sequestration limits the space available for the normal lung to develop, leading to pulmonary hypoplasia on the affected side with fewer airways and alveoli to support gas exchange after birth. Second, the same mass can physically compress adjacent lung tissue and airways, reducing expansion, causing atelectasis, and creating ventilation–perfusion mismatch. Together, these mechanisms explain why a large sequestration can produce respiratory insufficiency.