Pulmonary sequestration.
Pulmonary sequestration refers to the situation whereby a portion of lung tissue receives its blood supply from an anomalous systemic artery. Three main variants exist: intralobar, extralobar and communicating bronchopulmonary foregut malformations. Venous drainage is typically via a systemic vein, although drainage into the pulmonary veins is well documented. Pulmonary sequestrations are the second commonest congenital lung anomaly. Affected individuals often have other anomalies which are responsible for most of the mortality associated with sequestrations. Diagnosis requires a high index of suspicion particularly in any child with a chest x-ray suggesting the presence of a mass, those with recurrent chest infections and those with other anomalies seen with the pulmonary sequestration spectrum. Surgical excision is usually advised, although embolisation of the feeding vessel has a role in selected cases.