Thoracic MDCT findings of a combined congenital lung lesion: Bronchial atresia associated with congenital pulmonary airway malformation.

Purpose: To investigate the characteristic thoracic multidetector computed tomography (MDCT) findings of pathologically proven combined congenital lung lesion consisting of bronchial atresia (BA) and congenital pulmonary airway malformation (CPAM) in children.

Materials And Methods: All pediatric patients (age ≤ 18 years) with a known pathological diagnosis of a combined BA-CPAM congenital lung lesion, who underwent thoracic MDCT studies from January 2011 to January 2021 were included. Two pediatric radiologists independently evaluated thoracic MDCT studies for the presence of abnormalities in the lung, including nodule, mass, cyst, ground-glass opacity, and consolidation. When a lung abnormality was present, the number, size, composition (solid, cystic, or combination of both), borders (well-circumscribed vs. ill-defined), contrast enhancement pattern (nonenhancement vs. enhancement), and location (laterality, and lobar distribution) were also evaluated. Interobserver agreement between two independent reviewers was evaluated with κ statistics.

Results: Eighteen contrast-enhanced thoracic MDCT studies from 18 individual pediatric patients (8 males (44%) and 10 females (56%); mean age: 4.9 months; SD: 2.6; range: 1-10 months) with a pathological diagnosis of combined BA-CPAM congenital lung lesion comprised the final study population. The most frequent MDCT finding of combined BA-CPAM congenital lung lesion in children was a solitary (18/18; 100%), well-circumscribed (18/18; 100%), both solid and cystic (17/18; 94%) lesion with nonenhancing (17/17; 100%) nodule, reflecting the underlying BA component, adjacent to a well-circumscribed multicystic mass (18/18; 100%), representing the underlying CPAM component. This combined congenital lung lesion occurred in all lobes with similar frequency. There was almost perfect interobserver κ agreement between the two independent reviewers for detecting abnormalities on thoracic MDCT studies (k = 0.98).

Conclusion: The characteristic thoracic MDCT findings of a combined BA-CPAM congenital lung lesion are a solitary, well-circumscribed solid and multicystic mass, with a nonenhancing nodule, reflecting the BA component, adjacent to a cystic mass, representing the CPAM component. Accurate recognition of these characteristic MDCT findings of combined BA-CPAM congenital lung lesion has great potential to help differentiate this combined congenital lung lesion from other thoracic pathology in children.