Extralobar Sequestration

Extralobar sequestration

Explanation: Bronchopulmonary sequestration is a congenital malformation resulting from abnormal budding of the foregut, characterised by disorganised pulmonary parenchyma without normal pulmonary arterial or bronchial communications. Sequestration may be intralobar or extralobar (as in this case). Extralobar sequestrations have their own pleural covering, and venous drainage is systemic (to the azygous system in this case). Ninety percent of extralobar sequestrations are at the left base, contiguous with the diaphragm. Radiographically an extralobar sequestration usually appears as a homogeneous mass lesion. Antenatal ultrasound may identify the mass. Identification of the vascular connections is critical in making the diagnosis.

References: Webb WR, Higgins CB Thoracic Imaging, Lippincott, Williams & Wilkins, 2005.

Credit: Dr Laughlin Dawes