Wright JL, et al. - Clinical, radiological, and pathologic data were re-analyzed for 23 people with fibrotic interstitial lung disease and biopsy implying idiopathic pulmonary fibrosis or fibrotic hypersensitivity pneumonitis in order to recognize pathologic variables that aid to make an accurate distinction of idiopathic pulmonary fibrosis from fibrotic (chronic) hypersensitivity pneumonitis. Of idiopathic pulmonary fibrosis, a higher multidisciplinary discussion-based confidence was related to elderly age at diagnosis, male gender, higher forced vital capacity, and absence of ground glass changes. Pathologic variables correlated with a greater multidisciplinary discussion-based confidence of idiopathic pulmonary fibrosis and hypersensitivity pneumonitis involved a raised number of fibroblast foci/cm² and developed subpleural fibrosis; and a risen fraction of bronchioles with peribronchiolar metaplasia, raised foci of peribronchiolar metaplasia/cm², and presence of giant cells/granulomas, respectively. Hence, the results give direction in differentiating idiopathic pulmonary fibrosis from hypersensitivity pneumonitis, nevertheless, even while using these pathologic characteristics combined with clinical and radiologic information in a multidisciplinary discussion, a third of cases could not be confidently distinguished.