Bronchial Atresia Presenting With Recurrent Pneumonia in an Adult With Asthma: The Importance of Post-infectious Radiological Reassessment.

Congenital bronchial atresia (CBA) is a rare developmental anomaly characterized by focal obliteration of a segmental bronchus. It is typically asymptomatic and discovered incidentally; however, symptomatic presentations with recurrent respiratory infections have been reported, particularly in pediatric populations. We report a 39-year-old woman with well-controlled asthma who developed recurrent left lower lobe pneumonia following COVID-19 infection. Despite appropriate antibiotic therapy, she required hospitalization due to clinical recrudescence. Initial computed tomography (CT) demonstrated active inflammatory changes, while reassessment CT after clinical resolution revealed a mucus-filled, finger-like structure extending from the hilum without communication with the bronchial tree, along with regional emphysema, findings consistent with bronchial atresia of the left lower lobe, an atypical location. Conservative management was adopted following multidisciplinary discussion. This case highlights the importance of considering structural bronchial anomalies in recurrent localized pneumonia and demonstrates that bronchial atresia may present symptomatically in adults with unusual anatomical distributions, reinforcing the value of appropriately timed post-infectious radiological reassessment.