Table 1 Histological and clinical classification of idiopathic interstitial pneumonias*
Histological patternsClinical/radiological/pathological diagnosis
Usual interstitial pneumoniaIdiopathic pulmonary fibrosis/cryptogenic fibrosing alveolitis
Non-specific interstitial pneumoniaNon-specific interstitial pneumonia (provisional)†
Organising pneumoniaCryptogenic organising pneumonia‡
Diffuse alveolar damageAcute interstitial pneumonia
Respiratory bronchiolitisRespiratory bronchiolitis interstitial lung disease
Desquamative interstitial pneumoniaDesquamative interstitial pneumonia
Lymphoid interstitial pneumoniaLymphoid interstitial pneumonia

  • *Unclassifiable interstitial pneumonia: some cases are unclassifiable for a variety of reasons.

  • †A heterogeneous group with poorly characterised clinical and radiological features that needs further study.

  • ‡Cryptogenic organising pneumonia is the preferred term but it is synonymous with idiopathic bronchiolitis obliterans organising pneumonia.

  • Reproduced with permission from the American Thoracic Society/European Respiratory Society.1