C63-48 Anomalous Systemic Arterial Supply to the Right Lower Lobe Without True Sequestration in an Older Adult

Introduction Among congenital pulmonary anomalies, pulmonary sequestration is a rare condition distinguished by nonfunctional lung tissue supplied by an aberrant systemic artery. They can mimic chronic infection or other parenchymal lung disorders, making diagnosis difficult. Discerning actual sequestration from isolated systemic arterialization of normal lung (ISSNL) is important, as management and prognosis can differ significantly. Case Presentation A 65-year-old woman was followed in the pulmonary clinic for chronic dyspnea and a nonproductive cough that failed to improve despite optimized bronchodilator therapy. The patient underwent right heart catheterization, which excluded pulmonary hypertension. In addition, a barium swallow was negative. Non-contrast chest CT revealed an anomalous arterial branch in the right lower lobe, raising concern for pulmonary sequestration. Further evaluation with contrast-enhanced CT angiography demonstrated a systemic arterial supply arising from the abdominal aorta and venous drainage into a pulmonary vein, with preserved ventilation of the involved lung segment. These findings supported a diagnosis of isolated systemic arterial supply to normal lung parenchyma rather than intralobar sequestration. Discussion Differentiating between ISSNL and pulmonary sequestration is important because intralobar sequestration consists of nonfunctional lung tissue without a bronchial connection. In contrast, pulmonary sequestration involves a normal, aerated, and ventilated lung segment supplied by an anomalous systemic artery. ISSNL is a vascular variant, and its recognition avoids unnecessary surgical intervention and enables individualized management. Asymptomatic or minimally symptomatic patients can be managed conservatively with periodic imaging. Therefore, surgical or endovascular intervention may be served for those with significant shunt physiology, hemoptysis, or high-output cardiac failure. Conclusion This case highlights how a systemic arterial supply to a normally ventilated lung segment can easily be mistaken for pulmonary sequestration on imaging. Chest CT angiography is essential for diagnosis and can distinguish between vascular anomalies and actual sequestration. Recognizing isolated systemic arterial supply as a benign variant with a favorable prognosis and detailed clinical assessment to avoid unnecessary procedures. Figure 1: Aberrant arterial supply originating from the lower thoracic/upper abdominal aorta, and draining vein connecting right lower lobe pulmonary vein. This abstract is funded by: none