A72-04 The Mucus Plug That Unmasked a Congenital Secret: A Case of Bronchial Atresia in an Adult Female

Abstract Bronchial atresia is a rare congenital anomaly characterized by focal interruption of a bronchus with associated mucus impaction and distal air trapping. It is often detected incidentally on imaging in asymptomatic young adults. We report a 19-year-old female with no prior pulmonary disease who was found to have chronic right lower lobe mucus plugging and hyperlucency, initially concerning for allergic bronchopulmonary aspergillosis or endobronchial obstruction. Comprehensive evaluation, including bronchoscopy and serial CT imaging, ultimately confirmed undiagnosed bronchial atresia, emphasizing the need to consider congenital anomalies in persistent focal lung disease. Case Presentation A 19-year-old female smoker with no medical history presented with intermittent chest pain over one year. She initially presented to the emergency department with left flank pain; incidental CT findings revealed bronchiolar dilatation and mucus plugging in the right lower lobe, raising concern for allergic bronchopulmonary aspergillosis or chronic airway disease. Subsequent imaging demonstrated distal bronchial occlusion with air trapping and mucus impaction. Pulmonology evaluation prompted bronchoscopy which showed no endobronchial lesion; bronchoalveolar lavage was negative for malignancy, fungi, or mycobacteria. The patient’s symptoms improved briefly post-procedure. Subsequently, chest radiography again revealed a tubular debris-filled bronchus with adjacent hyperlucency. Repeat CT imaging demonstrated a blind-ending mucus-filled bronchus with distal hyperinflation and no interval change, consistent with congenital bronchial atresia. Discussion Bronchial atresia is a rare congenital anomaly characterized by focal interruption or obliteration of a bronchus, most often at the segmental or subsegmental level. This results in blind-ending bronchus with mucus accumulation, predisposing to recurrent infections, and formation of a bronchocele. It is frequently misdiagnosed as pulmonary sequestration, or bronchogenic cyst due to overlapping radiologic and clinical features, particularly in the prenatal and early postnatal period. Diagnosis is typically established by imaging modalities such as Chest CT, which reveals the characteristic mucus-filled bronchus with distal hyperinflation and can be further supported by bronchoscopy or histopathology demonstrating a blind-ending bronchus. Management remains controversial, with no standardized guidelines. Surgical resection (segmentectomy or lobectomy) is reserved for symptomatic patients or those with recurrent infections, while asymptomatic individuals may be managed conservatively with regular monitoring. Long-term follow-up is recommended to evaluate complications, monitor pulmonary function, and ensure stability in patients managed non-surgically or following resection This abstract is funded by: None