A 4 years child presents with a history of chronic left lower lobe pneumonitis. On contrast bronchography, the area involved with the pneumonitis does not fill whereas the area around it does fill. The most likely diagnosis ?

Ans. is 'b' i.e., Pulmonary sequestration Sequestrated lung has no connection to airway, so this pa does not fill on bronchography. Pulmonary sequestration o In this congenital anomaly, there is a discrete mass of lung tissue without any normal connection to the airway system. o It may be i) Intrapulmonary (intralobar) More common ii) Extrapulmonary (extralobar) o Sequestrated tissue receives its aerial supply from the systemic aeries (most commonly aoa). o It returns blood to the right side of hea through IVC (extrapulmonary sequestration) or pulmonary veins (intrapulmonary sequestration). o The sequestration functions as a space-occupying lesion within chest, it does not function in gas exchange, and does not contribute to a left to right shunt or dead space. o Gastric or pancreatic tissue may also be found in sequestrated segment. o Associated anomalies --> cystic adenomatoid malformation, congenital diaphragmatic hernia, esophageal cysts.