Lower Respiratory Tract

The respiratory system is crucial in the life of some overlapping specialties in medicine. In utero, the lung faces a change of the structure which is rarely seen in any other systems. The very myxoid tissue- and glycogen-rich pseudoglandular phase does not become mature that only in the late infancy and early childhood. Respiratory disease in the newborn is a well-known complication of prematurity, but in the last decade, a large number of entities have been added to the chILD or Children’s Interstitial Lung Disease adding complexity to the adult interstitial lung disease. In fact, youth may develop both pediatric and adult interstitial lung diseases, and pediatricians and pathologists should be aware of the pitfalls in not addressing an adult interstitial lung disease correctly in an adolescent. Some congenital anomalies of the abnormal driven foregut budding of the lung development may also be considered as an essential topic in studying pediatrics and adolescence. This chapter is completed with more than 400 photographs illustrating several lines of abnormal processes that may be present in a developing lung. Similar to non-neoplastic disease, both adult and specific pediatric neoplastic lung diseases need to get attention to avoid the possibility of pitfalls. In the last decade, some case reports of pulmonary carcinoma and malignant mesothelioma of the pleura have been reported in children adding complexity in carcinogenesis of this very complex organ. The molecular genetics has helped to clarify several carcinogenetic pathways not anymore limited to DICER1 gene mutations identified in pleuropulmonary blastoma.