Intralobar Sequestration
A non-functioning segment of lung tissue lacking a normal bronchial connection, sharing the visceral pleura with adjacent normal lung and supplied by an anomalous systemic artery.
Full Definition
Intralobar sequestration (ILS) is a bronchopulmonary malformation in which a mass of abnormal lung tissue is incorporated within the normal pulmonary lobe and shares its pleural envelope. Unlike extralobar sequestration, it has no separate pleural covering. It receives blood from an anomalous systemic artery, most commonly arising from the thoracic or abdominal aorta, and venous drainage is typically into the pulmonary veins. ILS is more often diagnosed in older children and adults than its extralobar counterpart and is less frequently associated with other congenital defects. Editors must not conflate the two sequestration subtypes, as they carry different prognostic and operative implications.
Usage
Usage note: Distinguish carefully from 'extralobar sequestration' in all reports; specify subtype rather than using the unqualified term 'sequestration'.
In Context
- "Histological sections confirmed intralobar sequestration within the left lower lobe, with no separate pleural investment identified." — Surgical pathology report
- "The radiological differential for the basal lung opacity included intralobar sequestration and consolidation secondary to recurrent infection." — Multidisciplinary team note