대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Cystic lung disease in Down syndrome (trisomy 21)

Radiologic Findings

Fig 1. Chest PA shows diffuse subpleural cysts in both lung field, especially left lung field.
Fig 2-4. CT scans reveal multiple small subpleural cysts in bilateral lungs with greater involvement of both upper lung zone.

Brief Review

Down syndrome (trisomy 21) is a common chromosomal disorder occurring in approximately 1 out of 750 liver births. Many factors contribute to the manifestation of respiratory system disorders among children with trisomy 21, encompassing structural abnormalities of the airways and lungs, recurrent lower respiratory tract infections and obstructive sleep apnoea.
Cystic lung disease in children with trisomy 21 was first described in 1986 by Joshi et al from the autopsy findings of two infants exhibiting lung cysts and congenital heart disease. On chest computed tomography (CT), it is characterized by a rim of small 1‐4 mm subpleural cysts at the periphery of the lung. The cysts are frequently but not exclusively symmetric and diffuse.
Subpleural cysts are not unique to trisomy 21; however, the most commonly described diagnostic entity associated with these small air‐filled cysts is trisomy 21. It represents cystic dilatations of the subpleural alveoli that communicate with dilated alveolar ducts. These are either primary (without any major lung abnormality) or in association with a co‐existing cardiovascular abnormality.
The patient described above was a 21-year-old man with known trisomy 21 and history of ASD (atrial septal defect) closure. This case highlights the importance of considering congenital conditions such as Down syndrome (trisomy 21) when observing diffuse subpleural cysts in pediatric patients or young patients without smoking history.

References

1. Singh, A., Coblentz, A., Hadian, F., Chami, R., Traubici, B., & Manson, D. E. (2023). Subpleural pulmonary cysts in children: Associations beyond Trisomy 21. Pediatric pulmonology, 58(12), 3498–3506.
2. Lim, M. T., Kapur, J., Reddy, B. K., Jingade, S. T., Goh, D. Y., & Ramamurthy, M. B. (2017). Subpleural Lung Cysts in Children with Trisomy 21. Annals of the Academy of Medicine, Singapore, 46(12), 472–475.

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