Background Although subpleural cysts are known to be associated with Down syndrome, their etiology and prevalence remains unknown. Objective To determine the prevalence of subpleural cysts in children with Down syndrome and the association with prematurity, congenital heart disease (CHD), extracorporeal membrane oxygenation (ECMO), and chronic ventilator support. Materials and methods A review of the CT examinations of 25 children with Down syndrome was performed to determine the presence, location, and distribution of cysts along with associated abnormalities. Charts were reviewed and coexistent diagnoses and past treatments were recorded. Results The prevalence of subpleural cysts was 36% with no significant association with CHD, ECMO, or chronic ventilator support. An association was found in the two children with a history of prematurity. The cysts were most commonly found in the anteromedial portion of the lung. Conclusion Subpleural cysts are common in Down syndrome and should not be confused with another pathological process. An association with prematurity was found, but the low number of children in this study makes the connection uncertain. The etiology remains unclear, but it has been hypothesized that the cysts are associated with lung hypoplasia.
