Extralobar Sequestration
A discrete mass of non-functioning lung tissue with its own pleural covering and systemic arterial supply, located outside the normal lung parenchyma.
Full Definition
Extralobar sequestration (ELS) is a congenital pulmonary malformation consisting of a discrete segment of non-aerated lung tissue that is entirely enclosed in its own pleural investment, distinguishing it from intralobar sequestration. It receives its blood supply from a systemic artery—most often the aorta—rather than from the pulmonary circulation. ELS is more commonly associated with other congenital anomalies, including congenital diaphragmatic hernia. In pathology reports, accurate identification of the pleural covering and the anomalous vessel is essential for correct classification. Editors should note the distinction from intralobar sequestration, as the two entities differ in clinical presentation, associated anomalies, and surgical management.
Usage
Usage note: Always specify 'extralobar' or 'intralobar' when reporting pulmonary sequestration; the unqualified term 'sequestration' is ambiguous in editorial contexts.
In Context
- "The autopsy report described a left-sided extralobar sequestration supplied by a branch of the descending thoracic aorta." — Paediatric autopsy report
- "Unlike intralobar sequestration, extralobar sequestration is enveloped in its own pleural covering and is more frequently associated with concurrent anomalies." — Surgical pathology synoptic report