Introduction
Interstitial lung diseases in the pediatric population are currently
characterized using a contemporary combined clinical and pathological
approach as proposed by Kurland et al, from the ChILD consortium. (1).
Childhood interstitial lung diseases (chILD) are now recognised as
distinct entities, owing to newly appreciated pathogeneses unique to the
pediatric age group, particularly evident in younger children. Advances
in the radiological, pathological and genetic bases in recent years have
prompted distinction of specialized subgroups of diffuse lung diseases
that present during infancy.
At the authors’ institution, we have recently noted a radiographic
pattern on computerised tomography (CT) of the chest, characterized by a
rim of small 1-4 mm subpleural cysts at the periphery of the lungs.
(images 1,2). The cysts are frequently but not exclusively symmetric and
diffuse. The most frequently described diagnostic entity associated with
these small air-filled cysts is Trisomy 21. (2, 3, 4, 5, 6, 7).
Pathological specimens in children with Trisomy 21 have demonstrated
cystic dilatations of the subpleural alveoli that communicate with
dilated alveolar ducts. (2,7). There are only occasional case reports
describing their occurrence in other genetic abnormalities, including
Trisomies 10 and 18, and Filamen A mutation (3,8,9, 10)
We have seen this CT pattern of subpleural cysts in children without
Trisomy 21. These are either primary (without any major lung
abnormality) or in association with a co-existing cardiovascular
abnormality. Through this retrospective analysis, we present a wider
population manifesting subpleural cysts. We propose that these
subpleural cysts are associated with pulmonary histological dysmaturity
or immaturity, similar to that
proposed in children with Down’s syndrome (2). Though rare, there is
currently limited literature regarding their further clinical
associations and their evolution over time.