All are true about extra lobar pulmonary sequestration except:
**Core Concept**
Pulmonary sequestration is a rare congenital anomaly characterized by the presence of a segment of lung tissue that is not connected to the airway and receives its blood supply from an anomalous systemic artery rather than the pulmonary artery. Extra lobar pulmonary sequestration refers to a type of sequestration that is located outside the normal lobar boundaries of the lung.
**Why the Correct Answer is Right**
Extra lobar pulmonary sequestration typically presents in adulthood, often as an asymptomatic mass or nodule on imaging studies. The anomalous systemic artery supplying the sequestrated lung tissue usually arises from the descending thoracic or abdominal aorta. The sequestrated tissue may be supplied by a bronchial artery or a systemic artery, and it does not communicate with the rest of the lung. This anomaly is often diagnosed incidentally during imaging studies for unrelated conditions.
**Why Each Wrong Option is Incorrect**
**Option A:** Extra lobar pulmonary sequestration is typically located within the lower lobes of the lung, but it can occur in any lobe, including the upper lobes. Therefore, this option is incorrect because it implies a specific location.
**Option B:** While the blood supply to the sequestrated lung tissue may arise from the descending thoracic or abdominal aorta, it is not limited to these locations. Other systemic arteries, such as the intercostal arteries, may also supply the sequestrated tissue.
**Option C:** The sequestrated tissue may be supplied by a bronchial artery or a systemic artery, but the primary blood supply is typically from a systemic artery, not a bronchial artery.
**Clinical Pearl / High-Yield Fact**
Pulmonary sequestration is often associated with other congenital anomalies, such as congenital diaphragmatic hernia or congenital heart disease. A high index of suspicion is necessary to diagnose this condition, especially in patients with a history of recurrent infections or hemoptysis.
**Correct Answer: A. Extra lobar pulmonary sequestration is typically located within the lower lobes of the lung.**