Pathophysiology
Clinical meaning
Pulmonary sequestration is a congenital malformation consisting of a mass of non-functioning lung tissue that lacks normal communication with the tracheobronchial tree and receives its blood supply from an anomalous systemic artery (usually from the thoracic or abdominal aorta). Intralobar sequestrations (75%) are contained within the visceral pleura and typically present in adolescents or adults with recurrent pneumonia in the same location. Extralobar sequestrations (25%) have their own pleural covering and are usually diagnosed in infancy, often associated with other congenital anomalies.