Abstract
Background: Small air filled peripheral subpleural cysts are a
well described feature of pulmonary anatomy at computerised tomographic
(CAT) scan in children with Trisomy 21, yet only anecdotally described
in association with other pathologies. The significance of these cysts
is unknown. Objective: To investigate and explore the
pathogenesis of these subpleural cysts in children. Materials
and Methods: A retrospective review of 16 cases with subpleural cysts
diagnosed on CT chest was performed. The distribution, location and
ancillary CT findings were recorded. Hospital charts were reviewed for
clinical details, especially cardiac abnormalities, pulmonary artery
hypertension (PAH) and genetic associations. Histopathological and
clinical correlative data were recorded. Results: 11/16
children (69%) were found to have an underlying chromosomal or genetic
abnormality, six of whom had Trisomy 21. The remaining 5/16 cases (21%)
had miscellaneous disorders without an identifiable genetic basis. The
most common co-morbidities were cardiac abnormalities (81%) and PAH
(62.5%). Regardless of their underlying etiologies, the cysts were
present bilaterally in most cases (14/16, 88%). We observed both the
postnatal development and the progression of cysts in our cohort
. On long term follow-up, there were five deaths (31%) and six
cases (38%) requiring maintenance oxygen therapy due to chronic
hypoxia. Two cases (12.5%) became completely asymptomatic after
correction of their underlying abnormalities. Conclusion:
Subpleural cysts are not exclusive to Trisomy 21 and may be seen in
other inherited or acquired causes, likely due to altered alveolar
growth. We suspect these cysts are a sign of an underlying developmental
disorder with variable clinical effect, especially in children with
congenital cardiac disease.