Congenital malformations
_Cystic adenomatoid
malformations
§Maturation arrest in lung segments
_Azyous lobe
§Superior apical bronchus grows medially instead of laterally; vein is at bottom of superior lobe
fissure
_Sequestration
–
§Accessory piece of lung that becomes disconnected from tracheobronchial tree and parasitizes systemic circulation from diaphragm.