The diagnosis of idiopathic interstitial pneumonias (IIPs) involves a
multidisciplinary scenario in which the radiologist assumes a key role. The
latest (2013) update of the IIP classification by the American Thoracic
Society/European Respiratory Society proposed some important changes to the
original classification of 2002. The novelties include the addition of a new
disease (idiopathic pleuroparenchymal fibroelastosis) and the subdivision of the
IIPs into four main groups: chronic fibrosing IIPs (idiopathic pulmonary
fibrosis and nonspecific interstitial pneumonia); smoking-related IIPs
(desquamative interstitial pneumonia and respiratory bronchiolitis-associated
interstitial lung disease); acute or subacute IIPs (cryptogenic organizing
pneumonia and acute interstitial pneumonia); rare IIPs (lymphoid interstitial
pneumonia and idiopathic pleuroparenchymal fibroelastosis); and the so-called
“unclassifiable” IIPs. In this study, we review the main clinical, tomographic,
and pathological characteristics of each IIP.