"Bridging bronchus". A previously undescribed airway anomaly

This report describes the clinical features and pathologic anatomy seen in an infant with anomalous bronchial branching and other congenital anomalies. The patient died of respiratory insufficiency and infection, possibly fostered by the malformed airway and a coexistent partial anomalous venous return. At autopsy, bronchial drainage of the right middle and lower lobes was provided by a large bronchial branch that originated in the left main-stem bronchus and bridged the mediastinum before entering the contralateral lung. Since crossed anatomic airway relationships after formation of primary branches are imcompatible with current concepts of embryologic lung development, a brief critical review of the pertinent literature is undertaken.