To describe the radiologic findings of the rare idiopathic interstitial pneumonias (IIPs) and how they correlate with their histologic patterns; To provide some differential diagnosis of these diseases.

In 2013, the revised American Thoracic Society/European Respiratory Society classification of idiopathic interstitial pneumonias distinguished two rare IIPs: Idiopathic lymphoid interstitial pneumonia (LIP) and idiopathic pleuroparenchymal fibroelastosis (PPFE). [1] As these conditions are still poorly recognized, they pose a diagnostic challenge so, these societies also highlighted the importance of a multidisciplinary approach to their correct diagnosis that encompasses clinical, radiologic and pathologic data. In the work-up of IIPs, only a multidisciplinary team will confidently decide which patients need a diagnostic biopsy and subsequently, integrate the...

PLEUROPARENCHYMAL FIBROELASTOSIS Radiographic Findings Chest radiographs are nonspecific for the diagnosis of PPFE, most commonly revealing apical reticulation, upper lobe volume loss and consequently upward hilar retraction (Fig. 3). HRCT Findings HRCT characteristically shows bilateral pleural thickening and subpleural reticulation, with upper lung predominance and accompanying volume loss causing upward hilar retraction (Fig. 4- 9). Associated features include architectural distortion, traction bronchiectasis and honeycombing (Fig. 6 and Fig. 7). Involvement by large cysts and bullae might be identified (Fig. 8), possibly explaining the high incidence...

There is considerable overlap between the rare IIPs’ radiologic and pathologic features. The definite diagnosis of these entities requires an agreement of a multidisciplinary team.

Contact Details: Dr. Miguel Correia da Silva Resident in training. Department of Radiology, Centro Hospitalar de São João -Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal Email: [email protected] Department of Radiology, Centro Hospitalar de São João: Thoracic Radiology Section: Dr. M. Rodrigues Dr. R. Cunha Resident in training: Dr. A.T. Vilares Dr. C. Sousa Dr. A. Carvalho Department of Pathology, Centro Hospitalar de São João: Dr. S. Guimarães

Travis WD, et al. An Official American Thoracic Society/European Respiratory Society Statement: Update of the International Multidisciplinary Classification of the Idiopathic Interstitial Pneumonias. Am J Respir Crit Care Med, 2013; 188(6): 733-748 Reddy TL, Tominaga M, Hansel DM, et al. Pleuroparenchymal fibroelastosis: a spectrum of histopathological and imaging phenotypes. Eur Respir J 2012; 40: 377–385 Bonifazi M, Montero MA, Renzoni EA. Idiopathic Pleuroparenchymal Fibroelastosis. Curr Pulmonol Rep (2017) 6:9–15 Cheng SKH, Chuah KL. Pleuroparenchymal Fibroelastosis of the Lung -A Review. Arch Pathol Lab Med. 2016;140:849–853...