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.
Exam relevance
Risk factors: - Congenital malformation (present from birth) - Family history of congenital lung malformations - Associated congenital anomalies (extralobar type: diaphragmatic hernia, pericardial defects) - Left lower lobe location (60-65% of cases) - Recurrent lower lobe pneumonia (intralobar type)
Diagnostics: - CT angiography showing anomalous systemic arterial blood supply (gold standard) - Chest X-ray showing recurrent consolidation in the same lower lobe location - MRI as an alternative for defining vascular anatomy - Doppler ultrasound (prenatal diagnosis) - Bronchoscopy showing absent bronchial communication - Angiography to map feeding vessels before surgery