Idiopathic Pleuroparenchymal Fibroelastosis

Abstract

Purpose of the review: Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare fibrosing lung disease, affecting the visceral pleura and the subpleural parenchyma with an upper lobe predilection, included as a distinct clinicopathologic entity in the latest international multidisciplinary classification of the idiopathic interstitial pneumonias (IIP). We aim to summarize the current evidence on IPPFE, in terms of clinical features and potential treatments.

Recent findings: Overall, there is increasing awareness of PPFE in association with a separate ILD pattern. Although an agreed consensus on diagnosis has yet to be defined, a list of radiological and histopathological criteria has been proposed. Due to the unfavorable risk-benefit profile of surgical lung biopsy in a significant proportion of patients, a potential role for transbronchial lung cryobiopsy has been suggested. At present, lung transplantation remains the only curative option.

Summary: The increasing awareness of this condition among specialists has led to more frequent identification of IPPFE. Large international studies are needed to better characterize pathogenesis and pheno/endotypes of disease, a key step towards the development of effective treatments.

Keywords: Clinical features; Diagnosis; Idiopathic interstitial lung disease; Pleuroparenchymal fibroelastosis; Review.

Fig. 1

a (Trasversal section) pleuroparenchymal irregularity with peaks of fibrosis around the pleural surfaces consistent with PPFE. The proximal airways are abnormally dilated (bronchiectatic), possibly the consequence of repeated infections. b (Sagittal section) there is pleuroparenchymal fibrosis with a clear mid and upper zone distribution. In the costophrenic angles, there is evidence of interstitial disease (limited honeycombing) with no conspicuous pleural disease

Fig. 2

a Section of a lung biopsy which displays subpleural and centrilobular fibroelastosis. The vessels show mild fibrointimal thickening (white arrow). b At higher magnification, the distinctive pattern of PPFE comprises intraalveolar fibrosis and interstitial elastosis (IAFE). At the edge, between the IAFE and the lung parenchyma, fibroblast foci are identified (black arrow)