A PUZZLING CASE OF RECURRENT PNEUMONIA: PLEUROPARENCHYMAL FIBROELASTOSIS

Abstract

TOPIC: Lung Pathology TYPE: Medical Student/Resident Case Reports INTRODUCTION: Pleuroparenchymal fibroelastosis (PPFE) is a fibroelastic process mainly affecting the visceral pleura and subpleural spaces with a propensity towards the upper lobes. It has unique clinical, pathological and radiological features1. CASE PRESENTATION: An 80 year old female with history of recurrent pneumonias and remote granulomatous disease presented with progressive dyspnea and fatigue. She denied other symptoms including chronic cough or sputum production or fever or chills. Chest X-ray showed extensive parenchymal and pleural fibrotic changes of the upper lobes. Pulmonary function tests suggested a restrictive pattern with reduced diffusion capacity (DLCO). Echocardiogram showed no significant abnormalities. Serial CT scans of the chest done over two years showed worsening pleuroparenchymal fibrotic changes of the upper lobes in a pattern very consistent with PPFE, with no evidence of honeycombing. This was likely idiopathic but potentially related to prior pneumonias and felt less likely to be related to her remote minimal parakeet exposure associated hypersensitivity pneumonitis. Her ANA titers were mildly elevated at 1:160 but further workup for auto-antibodies were negative including RF and CCP antibodies. ESR and CRP were minimally elevated. A bronchoscopy was offered to evaluate for infectious or other etiologies but she opted to wait. Her CT findings were however very consistent with PPFE and a provisional diagnosis of the same was made. DISCUSSION: PPFE is a rare but under-diagnosed type of interstitial lung disease. It is mostly idiopathic in nature but sometimes occurs as a late complication after lung transplantation. Although similar findings may be sometimes described in patients with autoimmune or connective tissue disease, it usually presents as a late complication and in certain patients with hypersensitivity pneumonitis, the idiopathic ones are best classified as PPFE1. PPFE is mostly seen in patients aged 40 to 70 years and presents as progressive dyspnea with or without cough. PPFE has to be differentiated from other upper lobe diseases like hypersensitivity pneumonia, sarcoidosis, idiopathic interstitial pneumonitis, non-tuberculous mycobacterial infection, pneumoconiosis, malignancy and apical pleural cap. High resolution CT scan remains the best diagnostic modality to show diffuse fibroelastic process predominantly affecting pleura and upper lobe parenchyma1. Pulmonary function test shows a restrictive pattern with reduced DLCO. No specific laboratory tests are diagnostic2. Surgical biopsies although not required for diagnosis can demonstrate intra-alveolar fibrosis and elastosis2. CONCLUSIONS: The prognosis of PPFE remains poor as no treatment is proven to be effective except therapeutic lung transplantation1. Further studies to understand pathogenesis, diagnostic markers and treatment modalities for this rare progressive disease are much warranted. REFERENCE #1: Chua F, Desai SR, Nicholson AG, et al. Pleuroparenchymal fibroelastosis. A review of clinical, radiological and pathological characteristics. Ann Am Thorac Soc 2019;16:1351-9. REFERENCE #2: Reddy TL, Tominaga M, Hansell DM, von der Thusen J, Rassl D, Parfrey H, Guy S, Twentyman O, Rice A, Maher TM, Renzoni EA, Wells AU, Nicholson AG. Pleuroparenchymal fibroelastosis: a spectrum of histopathological and imaging phenotypes. Eur Respir J. 2012 Aug;40(2):377-85. DISCLOSURES: No relevant relationships by Ansaam Daoud, source=Web Response No relevant relationships by Palak Rath, source=Web Response No relevant relationships by Lokesh Venkateshaiah, source=Web Response