Congenital bronchial atresia--presentation of three cases and a pictorial review.

Congenital bronchial atresia (CBA) is a rare anomaly that results from a congenital focal obliteration of a proximal segmental or subsegmental bronchus with the normal development of distal structures. The short atretic segment leads to accumulation of mucus within the distal bronchi to form a bronchocoele and underventilation of the affected part of the lung. The clinical and radiographic features of three cases of CBA are reported and the literature is reviewed. Radiologically, CBA is characterized by the presence of a branching opacity, the bronchocoele, radiating from the hilum surrounded by an area of hyperlucency. These features can be recognized on the chest radiograph but are more clearly defined by computed tomography. Fibreoptic bronchoscopy (FOB) is often required to exclude acquired proximal bronchial obstruction by tumour, foreign body or inflammatory stricture. In CBA a blind-ending bronchus may be revealed, although FOB is often normal. Bronchographic examination is generally abnormal but the appearances may be confusing and is rarely performed. Pathologically, CBA is characterized by a blind-ending bronchus associated with dilated distal bronchi containing impacted mucus. The surrounding lung parenchyma is hyperinflated due to collateral air drift. CBA can be identified accurately by imaging techniques which may make surgery unnecessary in asymptomatic cases.