Related Experiment Videos
The value of classifying interstitial pneumonitis in childhood according to defined histological patterns
A G Nicholson1, H Kim, B Corrin
1Department of Histopathology, Royal Brompton Hospital, London, UK.
Insights
Classifying pediatric interstitial pneumonitis using adult criteria is appropriate and informative. While
Area of Science:
- Pediatric Pulmonology
- Pediatric Pathology
- Interstitial Lung Diseases
Background:
- Interstitial pneumonitis in children is rare, often classified using adult disease patterns.
- The term 'chronic pneumonitis of infancy' has been proposed for specific infant interstitial lung disease patterns.
Purpose of the Study:
- To review pediatric interstitial pneumonitis cases.
- To determine the spectrum of histological patterns in children.
- To assess the appropriateness and value of adult classification in pediatric cases.
Main Methods:
- Retrospective review of 38 pediatric open lung biopsies.
- Histological classification based on established adult criteria.
- Analysis of clinical data including immune system associations and treatment response.
Main Results:
- Twenty-five biopsies showed diverse interstitial pneumonitis patterns.
- Three cases met criteria for chronic pneumonitis of infancy.
- Reactive pulmonary lymphoid hyperplasia was common (11 cases), often linked to immune issues.
- Desquamative and nonspecific interstitial pneumonitis were identified; usual interstitial pneumonitis was absent.
- Most patients improved with steroids but had residual lung deficits; younger age at presentation correlated with mortality.
Conclusions:
- Adult classification systems are suitable for pediatric interstitial pneumonitis, offering clinical utility.
- 'Chronic pneumonitis of infancy' represents a distinct histological pattern.
- Further research is needed to determine if 'chronic pneumonitis of infancy' is a separate disease or due to lung immaturity.
Aims:
Interstitial pneumonitis in children is very rare and most cases have been classified according to their counterparts in adults, although the term 'chronic pneumonitis of infancy' has recently been proposed for a particular pattern of interstitial lung disease in infants. We reviewed our paediatric cases of interstitial pneumonitis, first, to look at the spectrum of histological patterns found in this age group and, second, to determine whether the classification of such cases in childhood is both appropriate and worthwhile.
Methods And Results:
Twenty-five of 38 open lung biopsies showed an overlapping spectrum of interstitial pneumonitis, including three cases that fulfilled the histological criteria for chronic pneumonitis of infancy. There were 11 cases of reactive pulmonary lymphoid hyperplasia (either lymphoid interstitial pneumonitis or follicular bronchiolitis), five of which were associated with abnormalities of the immune system. Four cases were classified as desquamative interstitial pneumonitis and the remaining seven cases were classified as nonspecific interstitial pneumonitis. There were no cases with the histological features of usual interstitial pneumonitis. Most patients responded to steroids but tended to have a residual deficit in lung function. Mortality appeared to be associated with presentation at a young age.
Conclusion:
Classification of interstitial pneumonitis according to their adult counterparts is appropriate for this younger age group and can provide valuable information for the clinician. The term 'chronic pneumonitis of infancy' refers to a specific histological pattern, but whether it represents a separate disease or a reflection of pulmonary immaturity remains to be proven.