Table II.

American thoracic Society/European respiratory society classification of IIP from 2013.

IIP classification	Pathology
Major IIP	Idiopathic pulmonary fibrosis
	Idiopathic nonspecific interstitial pneumonia
	Respiratory bronchiolitis interstitial lung disease
	Desquamative interstitial pneumonia
	Cryptogenic organized pneumonia
	Acute interstitial pneumonia
Rare IIP	Idiopathic lymphocytic interstitial pneumonia
	Idiopathic pleuroparenchymal fibroelastosis
Unclassified IIP	–

IIP, idiopathic interstitial pneumonia.