ABSTRACT
Idiopathic pulmonary fibrosis (IPF) is classified among the major idiopathic interstitial pneumonias. The radiological pattern of IPF is the usual interstitial pneumonia. In order to diagnose IPF, it is necessary to exclude other diseases that may cause the usual interstitial pneumonia pattern. Pleuroparenchymal fibroelastosis is a rare fibrotic interstitial lung disease. Pleuroparenchymal fibroelastosis mainly tends to involve the upper lobes, visceral pleura and subpleural parenchyma, and as it progresses, it can involve the entire lung. Although the etiology is not fully known, most of the cases are idiopathic, a smaller number are due to familial and secondary causes. It has a poor prognosis, especially in those with a family history, in young, female patients, and in those with the usual interstitial pneumonia pattern in the lower lobes. In cases with interstitial lung disease and radiologically showing pulmonary fibrosis for known or unknown reasons other than IPF, the presence of at least two of the three criteria defined as worsening of respiratory symptoms, functional deterioration and radiological progression within the last year is considered progressive pulmonary fibrosis (PPF). In this article, we aimed to present and discuss the definition of PPF and pleuroparenchymal fibroelastosis, diagnostic criteria, and the approach to IPF according to the ATS/ERS/JRS/ALAT 2022 IPF diagnostic guide.