Pulmonary Sequestration in a Septuagenarian: A Rare Congenital Lung Lesion Diagnosed in Adulthood

Introduction Pulmonary sequestration (PS) is a rare congenital pulmonary malformation characterized by non-functioning lung tissue that lacks normal communication with the tracheobronchial tree and receives systemic arterial blood supply. While it is often diagnosed in childhood due to recurrent infections, incidental detection in asymptomatic adults is uncommon and can pose a diagnostic challenge, especially when differentiating it from malignant pulmonary lesions. Case Details: We report the case of a 68-year-old female who was incidentally found to have a left lower lobe mass during routine imaging. Initial CT revealed a 3.2 cm triangular mass in the posteromedial aspect of the left lower lobe abutting the descending thoracic aorta. PET imaging showed the lesion to be non-FDG avid with mild adjacent atelectasis. Subsequent CT angiography demonstrated a feeding artery originating from the descending aorta, confirming the diagnosis of pulmonary sequestration. The patient was asymptomatic and declined surgical intervention. She is being managed conservatively with serial imaging, which was showing stability of the lesion over follow-up. Conclusion: Introlobar pulmonary sequestrants are often diagnosed in young and middle aged adults. Their occurrence in older adults is rarely reported. Their close resemblance with malignancy in these demographics makes it a diagnostic challenge. Multimodal imaging, including PET and CTA, is crucial for accurate diagnosis. In asymptomatic patients without complications, conservative management with radiologic surveillance may be a safe and appropriate approach.