Introduction to Developmental Abnormalities

The introduction to developmental abnormalities summarizes the types of developmental thoracic anomalies and variants that may affect the adult patient. These abnormalities can be categorized based on their anatomic location within the thorax and may affect the airways, lung, pleura, mediastinum, heart, blood vessels, diaphragm and chest wall. Assessment of central tracheobronchial morphology is important in the determination of visceral-atrial situs. Airway anatomic variants are common but do not usually produce symptoms or require treatment. There is great variability in the fissural anatomy of the lung with frequent incomplete and accessory fissures. Intralobar sequestration may affect children, adolescents or adults and is confirmed by visualization of systemic blood supply to abnormal lung parenchyma. Developmental abnormalities may also affect the mediastinum and the cardiovascular system. Symptomatic patients may present in adulthood with intra- and extracardiac shunt lesions. Developmental lesions may also affect the systemic arteries and veins and may result in anomalous pulmonary venous return to the right heart. These lesions are typically evaluated with chest CT and/or MRI. Diaphragmatic developmental lesions in adults include Bochdalek and Morgagni hernias. Congenital anomalies may also affect the chest wall osseous structures and soft tissues.