Pleuroparenchymal fibroelastosis: is it also an idiopathic entity?

Pleuroparenchymal fibroelastosis (PPFE) is a rare disease that has been recently included in the updated consensus on idiopathic interstitial pneumonias. It shares some clinical features with other chronic interstitial pneumonias (dyspnea, dry cough), and is radiologically characterized by pleural and subpleural parenchymal fibrosis and elastosis, mainly in the upper lobes. The main histological findings include pleural fibrosis and prominent subpleural and parenchymal fibroelastosis. Its characterization is based on the increasing number of cases reported in the literature, so several aspects of the etiology, pathogenesis and natural history are still unknown. Although some cases have been described as idiopathic, PPFE has been reported as a complication after bone marrow transplantation, lung transplantation and chemotherapy, especially with alkylating agents.Spontaneous or iatrogenic pneumothorax is a frequently reported complication of invasive diagnostic tests for identifying PPFE. The disease course is variable, ranging from slow progression to rapid clinical deterioration. No treatment has shown evidence of efficacy, and lung transplantation remains the only option for patients who fulfill the diagnostic criteria for this option. Recognizing and disseminating the specific features of PPFE is essential to raise the level of clinical suspicion for this entity, and to implement appropriate multidisciplinary diagnostic management.