Pulmonary sequestration in a septuagenarian: a rare congenital lung lesion diagnosed in adulthood

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. We report the case of a 70-year-old female who was incidentally found to have a left lower lobe mass on 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, and CT angiography demonstrated a feeding artery arising 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 has shown that the lesion remains stable over follow-up. Intralobar pulmonary sequestrants in older adults are rarely reported. Their close resemblance to malignancy in this population makes diagnosis challenging. Multimodal imaging, including PET and CTA, is crucial for accurate diagnosis. In asymptomatic patients without complications, conservative management with radiological surveillance may be a safe and appropriate approach.