Emphysema and a Hilar Mass in a Young Woman

Abstract

SESSION TITLE: Imaging SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Bronchial atresia is a congenital anomaly affecting the structure of the bronchial tree, wherein a disruption occurs in the bronchus following its formation. This disorder is often asymptomatic and diagnosed incidentally on chest imaging. CASE PRESENTATION: A 22-year old female non-smoker presented for evaluation of dyspnea on exertion and “congenital emphysema.” This finding was first noted incidentally two years prior when she was diagnosed with bilateral pulmonary emboli, secondary to the use of estrogen-containing contraception. Her medical history was otherwise unremarkable. She reported mild dyspnea on exertion and intermittent pleuritic chest pain. Vital signs were within normal limits, notable for oxygen saturation of 99% on room air. On physical examination, lung sounds were clear to auscultation, without audible wheezes or crackles with normal respiratory effort. No clubbing was present. Remainder of exam was unremarkable. Alpha-1-antitrypsin level was within normal limits (185 mg/dL). Pulmonary function tests (PFTs) were also normal. A CT chest demonstrated emphysematous changes in the right upper lobe, with a soft tissue density measuring 3.3x1.5 cm at the right superior hilum, consistent with a bronchocele. Further examination of the bronchial tree demonstrated atresia of the apical and posterior segments of the right upper lobe (Figure 1). DISCUSSION: Bronchial atresia is a condition of structural disruption in the bronchial tree. This anatomic anomaly is thought to be due to an insult, likely ischemic, during embryonic development in which the cells at the tip of the bronchial bud are disrupted from the bud itself. The distal bronchial tree forms normally, despite lack of communication to the proximal bronchus. The classic appearance on CT includes focal emphysema distal to the non-communicating airway, and a mucocele immediately distal to the site of atresia near the hilum. Aeration of the distal alveoli is theorized to result from collateral air-flow through intraalveolar pores of Kohn and bronchoalveolar channels of Lambert. Due to lack of communication with the proximal airway, air trapping occurs resulting in the appearance of emphysema. The distal bronchi function normally, causing mucus plugging at the atretic bronchus. Patients are generally asymptomatic, and this condition is most often discovered incidentally in adolescence. Treatment is usually not necessary; rarely surgery is indicated for recurrent infections. Most cases involve the left upper lobe, but cases at the right upper and middle lobe subsegments have been reported as well. CONCLUSIONS: Our patient presented with CT findings characteristic for bronchial atresia, with focal emphysema in the apicoposterior segments of the right upper lobe and mucocele distal to the atretic bronchus. Her pleuritic pain is felt to be related to the bulla abutting the pleura, and is treated with albuterol as needed. Reference #1: Gipson et al. Bronchial atresia. Radiographics 2009; 29:1531-5. DISCLOSURE: The following authors have nothing to disclose: Sarah Williams, Bethany Weiler-Lisowski, Avelino Verceles, Peter Bergquist No Product/Research Disclosure Information