Interstitial Lung Disease

Interstitial lung disease (ILD) is not a single disease but includes a group of diffuse parenchymal disorders that primarily affect the pulmonary interstitium. ILD can occur secondary to specific causes or may be classified as an idiopathic interstitial pneumonia (IIP), a group of well-defined ILDs that lack a clear predisposing factor or underlying pathophysiology. Accurate classification of ILD often requires a multidisciplinary approach that incorporates input from a multidisciplinary team including pulmonologists, chest radiologists, and thoracic pathologists. In their most severe forms, these diseases can lead to progressive respiratory failure and eventually death. Despite notable advances in imaging techniques and treatment approach, progress has been challenged by a poor understanding of pathological mechanisms and patient heterogeneity, including variable progression. Thus, the diagnostic pathway is being continually refined, with updates in disease classification, introduction of novel tools such as transbronchial cryobiopsy, and a move toward molecular-driven diagnostic approaches.