Intralobar pulmonary sequestration.

Intralobar pulmonary sequestration is a rare congenital anomaly, comprising a mass of non-functioning lung tissue, without normal bronchial and vascular connections. The condition has two distinct clinical presentations: 1. In the 1st year of life, it may present as the site of a significant arterio-venous shunt, and then is usually associated with other cardiac anomalies, becoming defined in the course of appropriate cardiovascular investigations. 2. In older children, the condition becomes manifest because of persistent radiological changes and inadequate response to treatment, following one or more bouts of respiratory infection. Occlusion of the shunt or removal of the sequestration is the definitive management; the importance of the condition relates to the need to consider the diagnosis in evaluating the clinical presentations indicated above.