Focal Lung Disorders

Abstract

Pulmonary cysts seen on plain chest radiographs as completely or partially air-filled, round masses may be congenital, infectious/inflammatory, traumatic, or neoplastic in origin. The differential diagnosis can be refined based on the age of the patient (neonate and young infant vs. child) and distribution within the lungs (unilateral vs. bilateral), as well as the clinical presentation and the presence of other findings such as nodules or wedge-shaped opacities.In neonates or young infants, unilateral findings most often represent bronchopulmonary foregut malformations, while bilateral involvement suggests chronic lung disease of prematurity (Table 7.1). Young children most commonly present with symptoms of infection with or without an underlying congenital anomaly. A solitary lesion suggests a congenital anomaly or bacterial infection in a previously healthy child. If findings are bilateral, a systemic disease should be considered. Langerhans histiocytosis and cystic fibrosis (CF) are bilateral upper lung zone predominant diseases early on, while septic emboli involve the lower lobes preferentially. The presence of nodules and cysts suggests conditions such as Langerhans cell histiocytosis (LCH), granulomatosis with polyangiitis (previously known as Wegener granulomatosis), cystic fibrosis, and papillomatosis. The presence of wedge-shaped opacities suggests a vascular etiology as in granulomatosis with polyangiitis or septic emboli (Table 7.2).