This chapter will discuss lung disorders that present throughout the childhood years, including infancy and the perinatal period. Some structural abnormalities are now detected earlier with recent advances in prenatal ultrasound. Areas considered include congenital malformations and disease processes associated with the transition from an intrauterine to an extrauterine existence, particularly when this occurs preterm. Cystic fibrosis (CF) and other inheritable conditions that typically present first in the pediatric age range will also will be covered. The pediatric aspects of conditions such as infection and tumors are also included but entities typically encountered in adults that rarely affect children will only be cross-referenced.
Congenital malformations are morphological defects in part of an organ, a complete organ or a larger region of the body, due to an intrinsically abnormal developmental process. A morphological defect of the same structures due to the extrinsic breakdown of, or interference with, an originally normal developmental process is termed a disruption. These may be difficult to distinguish, especially if the disruption has occurred early in gestation. Some malformations are presumed multifactorial, due to interactions between genetic factors and environmental agents; others are purely environmental. It may be difficult to be sure where, in this etiological spectrum, some malformations should be placed. To understand defects in lung development it is essential to remember the embryology outlined in Chapter 1.