Intralobar sequestrations represent what percentage of cases?

• A. 75%
• B. 25%
• C. 50%
• D. 10%

Answer: (A)

Intralobar sequestration is the more common form of pulmonary sequestration. It occurs when nonfunctioning lung tissue lies within a normal lobe and shares the lung’s pleura, and it accounts for the majority of cases—roughly three-quarters. The remaining portion represents the extralobar form, which has its own pleural covering and is less common. So the best answer reflects that intralobar sequestration makes up the vast majority of cases.