Table 1.

Classification of childhood ILD

Disorders more prevalent in infancy
Category	Specific Diagnoses*
Diffuse developmental disorders	Acinar dysplasia Congenital alveolar dysplasia Alveolar-capillary dysplasia with pulmonary vein misalignment
Lung growth abnormalities	Pulmonary hypoplasia Chronic neonatal lung disease (BPD) Associated chromosomal disorders (Trisomy 21, others) Associated with congenital heart disease
Specific conditions of uncertain etiology	Neuroendocrine cell hyperplasia of infancy (NEHI) Pulmonary interstitial glycogenosis (PIG)
Surfactant dysfunction	Mutations in SFTPB, SFTPC, ABCA3, NKX2.1/TTF1 Histology consistent with surfactant dysfunction disorder but without recognized genetic etiology
Disorders not specific to infancy
Disorders of normal host (immune-competent)	Infectious/post-infectious Aspiration Related to environmental agents (hypersensitivity pneumonitis, toxic inhalation) Eosinophilic pneumonia
Disorders related to systemic disease processes	Immune-related disorders (SLE, polymyositis/dermatomyositis, systemic sclerosis) Storage diseases Sarcoidosis Langerhans cell histiocytosis Malignant infiltrates
Disorders of immune-compromised host	Opportunistic infections Transplantation/rejection syndromes
Disease masquerading as ILDs	Arterial hypertensive vasculopathy Veno-occlusive disease Lymphatic disorders
Unclassified	Conditions that do not clearly fit into specific category (i.e. end-stage disease, inadequate or non-diagnostic biopsy specimen)

Abbreviations: BPD=bronchopulmonary dysplasia; ILD=interstitial lung disease; SLE=systemic lupus erythematosis;

^*Includes examples of specific diagnoses classified within each category.

Adapted from [1] Deutsch et al, AJRCCM 2007.