CONGENITAL BRONCHIAL ATRESIA MASQUERADING AS A LUNG MASS

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SESSION TITLE: Medical Student/Resident Lung Pathology SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Congenital bronchial atresia (CBA) is a rare congenital abnormality resulting from the focal interruption of a lobar, segmental, or subsegmental bronchus. As most patients are asymptomatic, it is difficult to estimate its prevalence. We present a case of a young Hispanic female who was incidentally diagnosed with congenital bronchial atresia during bronchoscopy for a suspected mass. CASE PRESENTATION: A 21 y/o Hispanic female with no medical history was referred to the pulmonology clinic for evaluation of a RUL lung nodule seen on chest radiography during work-up for RUQ pain. A CAT scan revealed a 3 cm RUL mass with surrounding pulmonary hyperlucency. On presentation, the patient denied constitutional or pulmonary symptoms concerning for infection or malignancy. Physical exam revealed decreased breath sounds over the RUL lung field. Initial work-up was negative for endemic infections such as TB or cocci. She also denied recurrent pulmonary infections or lung disease. The patient underwent bronchoscopy with BAL, revealing an anatomical variant of 4-RUL segments with apical posterior segment stenosis visualized but not amenable to passage of the bronchoscope and without end-bronchial or mucosal abnormalities. BAL cultures for AFB, fungal, and bacteria were negative. BAL cocci antigen as well as serum IgG and IgM were negative. Serum QTB and cytology were also negative. At that point, the diagnosis of congenital bronchial atresia was made. DISCUSSION: Bronchial atresia typically is identified as an incidental finding on chest radiography in an asymptomatic older child or adult. The left upper lobe bronchus is most commonly involved, followed by the RUL, RML, and RLL. Due to lack of communication with the normal tracheobronchial tree, infection is uncommon. Radiographic appearance is due to mucoid impaction distal to the occluded bronchus and hyperexpansion of the affected pulmonary segment. Specifically, a perihilar mass is surrounded by a halo of lung that is hyperlucent due to collateral ventilation and gas trapping. Regarding treatment, there is much debate. Some specialists prefer surgery on all patients while others prefer a conservative approach, especially in absence of serious symptoms, such as secondary infection. CONCLUSIONS: The exact cause of bronchial atresia is unknown. It is hypothesized to occur as a focal bronchial interruption before birth. Regardless, most patients present asymptomatically, and many are discovered incidentally on chest imaging. Awareness and high level of suspicion are required to prevent unnecessary additional procedures or surgeries. Review of imaging may help determine chronicity and certain factors such as surrounding hyperluceny, as in our patient, can help lead to this diagnosis. A conservative approach is recommended by most specialists in our review of literature. Surgery should be reserved for those with secondary infections and recurrent symptoms. Reference #1: Wang, Yuqi et al. “Congenital bronchial atresia: diagnosis and treatment.” International journal of medical sciences vol. 9,3 (2012): 207-12. doi:10.7150/ijms.3690. Reference #2: Zylak CJ, Eyler WR, Spizarny DL, et al. Developmental lung anomalies in the adult: radiologic-pathologic correlation. Radiographics 2002;S25–43. DISCLOSURES: No relevant relationships by Katherine Gross, source=Web Response No relevant relationships by Ricardo Herrera, source=Web Response No relevant relationships by Jonathan Munoz, source=Web Response