Bronchial atresia mimicking Swyer–James syndrome

). The correlation of CT and bronchoscopic findings established the diagnosis of congenital bronchial atresia. Bronchial atresia is a rare congenital abnormality in which the bronchus lacks central airway communication 1 . It is hypothesized to occur as focal bronchial interruption due to intrauterine ischemia after the 16th week of gestation 2 . Chest x-ray findings typically show hyperlucency, hilar mass, or both. CT is the gold standard for its diagnosis and the main findings are bronchocele, hyperinflation of the distal lung, and hypovascularity 3,4 . The main characteristic of bronchoceles is the mucoid impaction of atretic segment. Hyperinflation can be explained by collateral ventilation through the pores of Kohn, bronchoalveolar channels of Lambert, or via air-trapping due to check valve mechanism 5 . Despite these almost pathognomonic findings, it is necessary to differentiate unilateral hyperlucency from Swyer-James syndrome. It describes an acquired condition that usually develops during childhood as a sequel of post-infectious bronchitis obliterans, leading to the dilation and destruction of lung parenchyma with air trapping 1 and underdevelopment of the peripheral pulmonary vessels. The CT finding of a normal distal bronchial branch pattern without a connection between the distal and central airways is essential to differentiate bronchial atresia from Swyer-James syndrome 1 . Other congenital situations that should be included in differential diagnosis are congenital lobar emphysema, pulmonary sequestration and congenital cystic adenomatoid malformation, as there are possible common pathogenic pathways. During adulthood, the surgical treatment is meant for patients who present repeated infections 6 .