Pulmonary Developmental Disorders in Adults: An Integrative Review of Embryology, Pathogenesis, Imaging, and...

Pulmonary developmental disorders comprise a heterogeneous group of congenital abnormalities involving the airways, lung parenchyma, pulmonary vasculature, or overlapping developmental pathways. Although these conditions commonly present during infancy or childhood, many remain clinically silent until adulthood, when they are discovered incidentally or manifest with recurrent respiratory symptoms such as infection, hemoptysis, or progressive dyspnea. These abnormalities may be broadly categorized into airway, vascular, parenchymal, and mixed developmental anomalies. Airway abnormalities include congenital tracheobronchomegaly, branching anomalies of the tracheobronchial tree, bronchial atresia, bronchogenic cysts, congenital pulmonary airway malformations (CPAM), and bronchopulmonary sequestration (BPS). Vascular anomalies include pulmonary artery sling, proximal interruption of the pulmonary artery, Scimitar syndrome, and meandering pulmonary veins. Parenchymal disorders encompass congenital lobar overinflation and pulmonary hypoplasia. Increasing recognition of overlapping lesions, particularly combinations of CPAM, sequestration, and bronchial atresia, has challenged traditional compartmental classification systems and supports a developmental spectrum model. This review synthesizes contemporary concepts regarding embryologic mechanisms, pathogenesis, imaging findings, and management of these entities in adults. Particular emphasis is placed on imaging evaluation with CT and MRI, updated terminology, evolving molecular understanding of CPAMs, including lesions with malignant potential, and distinctions between congenital sequestration and pseudosequestration. Recognition of these disorders and their associated anomalies is essential for accurate diagnosis, appropriate management, and surgical planning in adult patients.