Pulmonary Sequestration - Extralobar Sequestration

Extralobar Sequestration

·The extralobar variety accounts for 25 percent of all sequestrations.

·ELS usually presents in infancy with respiratory compromise.

·Develops as an accessory lung contained within its own pleura.

·ELS has a male predominance (80%).

·Related to the left hemidiaphragm in 90% of cases.

·ELS may present as a subdiaphragmatic or retroperitoneal mass.

·In general, the arterial supply of ELS comes from an aberrant vessel arising from the thoracic aorta.

·It usually drains via the systemic venous system to the right atrium, vena cava, or azygous systems.

·Congenital anomalies occur more frequently in patients with ELS than ILS.

·Associated anomalies include Congenital cystic adenomatoid malformation (CCAM), congenital diaphragmatic hernia, vertebral anomalies, congenital heart disease, pulmonary hypoplasia, and colonic duplication

·Since it is enveloped in its own pleural sac, it rarely gets infected so almost always presents as a homogeneous soft tissue mass.

·The mass may be closely associated with the esophagus, and fistulae may develop.