Table 2.

Classification scheme for paediatric diffuse lung disease [48]

I. Disorders more prevalent in infancy A. Diffuse developmental disorders  1. Acinar dysplasia  2. Congenital alveolar dysplasia  3. Alveolar-capillary dysplasia with pulmonary vein misalignment B. Growth abnormalities  1. Pulmonary hypoplasia  2. Chronic neonatal lung disease   A. Prematurity-related chronic lung disease (bronchopulmonary dysplasia)   B. Acquired chronic lung disease in term infants  3. Structural pulmonary changes with chromosomal abnormalities   A. Trisomy 21   B. Others  4. Associated with congenital heart disease in chromosomally normal children C. Specific conditions of undefined aetiology  1. Pulmonary interstitial glycogenosis  2. Neuroendocrine cell hyperplasia of infancy D. Surfactant dysfunction mutations and related disorders  1. SPFTB genetic mutations – PAP and variant dominant histologic pattern  2. SPFTC genetic mutations – CPI dominant histologic pattern; also DIP and NSIP  3. ABCA3 genetic mutations – PAP variant dominant pattern; also CPI, DIP, NSIP  4. Others with histology consistent with surfactant dysfunction disorder without a yet recognised genetic disorder

II. Disorders not specific to infancy A. Disorders of the normal host  1. Infectious and postinfectious processes  2. Disorders related to environmental agents: hypersensitivity pneumonia, toxic inhalation  3. Aspiration syndromes  4. Eosinophilic syndromes B. Disorders related to systemic disease processes  1. Immune-related disorders  2. Storage disease  3. Sarcoidosis  4. Langerhans cell histiocytosis  5. Malignant infiltrates C. Disorders of the immunocompromised host  1. Opportunistic infection  2. Disorders related to therapeutic intervention  3. Disorders related to transplantation and rejection syndromes  4. Diffuse alveolar damage of unknown aetiology D. Disorders masquerading as interstitial disease  1. Arterial hypertensive vasculopathy  2. Congestive vasculopathy, including veno-occlusive disease  3. Lymphatic disorders  4. Congestive changes related to cardiac dysfunction

III. Unclassified – includes end-stage disease, nondiagnostic biopsies and those with inadequate material

CPI, chronic pneumonitis of infancy; DIP, desquamative cell interstitial pneumonia; NISP, nonspecific interstitial pneumonia; PAP, pulmonary alveolar proteinosis.