Pleuroparenchymal fibroelastosis (PPFE) is a recently described rare, benign entity. About half of cases are felt to be idiopathic, with the other half secondary to underlying diseases or conditions (e.g. transplantation). Idiopathic cases belong to the group of idiopathic interstitial pneumonias.
It is a considered rare disorder however it is very likely both under-recognized and misdiagnosed 5. Median age at presentation in reported cases approximates the fifth decade of life, with age distribution likely bimodal 8:
- early peak in the third decade
- late peak in the sixth decade
No gender predilection has been reported, and patients are most often non-smokers 2,4,8.
Most often significant chronic respiratory symptoms, which may include:
- non-productive cough
- dyspnea, either on exertion or in a worsening course
- frequent airway infections
Signs may include:
- positive autoimmune titers
- reduced lung function of mixed (obstructive and restrictive) pattern (reduced forced expiratory in 1st second (FEV1), reduced forced vital capacity (FVC), reduced diffusing capacity for carbon monoxide (DLCO))
The pathophysiology is unknown. PPFE is characterized by predominantly upper lobe pleural and subjacent parenchymal fibrosis (the latter being intra-alveolar with accompanying elastosis of the alveolar walls).
The etiology remains unknown. Familial cases have been reported, especially in young women 8.
Roughly half of cases occur as a sequela of lung transplantation 6,8 or bone marrow transplantation 8,10. About one-tenth might even be drug-induced by chemotherapy 8.
Typical features include the abundance of short, curled, and randomly oriented elastic fibers, resulting in elastic fibrosis of the visceral pleura. These may be identifiable on standard hematoxylin and eosin (H&E) stains, however elastic fiber stains (e.g. Elastica van Gieson EVG) may be useful in cases of doubt.
Chest x-rays may be normal or present non-specific findings comprising:
Optimally performed as high-resolution computed tomography (HRCT) of the lung, it may depict:
- marked bilateral apical pleural thickening
- apical caps
- architectural distortion, possibly leading to
- traction bronchiectasis
- upper volume loss
- peripheral consolidation
- reticular abnormalities, including
- lymphadenopathy: mediastinal and/or axillary
Treatment and prognosis
PPFE usually shows a progressive clinical course and carries a poor prognosis. There is currently no specific therapy. Medical options with steroids, cyclophosphamide, azathioprine, N-acetylcysteine, azithromycin, sulfamethoxazole and trimethoprim may all be tried. In progressive cases, lung transplantation may be required.
History and etymology
It is thought to have been first described by S K Frankel et al. in 2004 2.
For the relatively rare combination of both pleural and interstitial fibrosis may include 5,8:
- 1. Travis WD, Costabel U, Hansell DM 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): 733-48. doi:10.1164/rccm.201308-1483ST - Pubmed citation
- 2. Frankel SK, Cool CD, Lynch DA et-al. Idiopathic pleuroparenchymal fibroelastosis: description of a novel clinicopathologic entity. Chest. 2004;126 (6): 2007-13. doi:10.1378/chest.126.6.2007 - Pubmed citation
- 3. Piciucchi S, Tomassetti S, Casoni G et-al. High resolution CT and histological findings in idiopathic pleuroparenchymal fibroelastosis: features and differential diagnosis. Respir. Res. 2011;12 (1): 111. doi:10.1186/1465-9921-12-111 - Free text at pubmed - Pubmed citation
- 4. Reddy TL, Tominaga M, Hansell DM et-al. Pleuroparenchymal fibroelastosis: a spectrum of histopathological and imaging phenotypes. Eur. Respir. J. 2012;40 (2): 377-85. doi:10.1183/09031936.00165111 - Pubmed citation
- 5. Becker CD, Gil J, Padilla ML. Idiopathic pleuroparenchymal fibroelastosis: an unrecognized or misdiagnosed entity?. Mod. Pathol. 2008;21 (6): 784-7. doi:10.1038/modpathol.2008.56 - Pubmed citation
- 6. Hirota T, Fujita M, Matsumoto T et-al. Pleuroparenchymal fibroelastosis as a manifestation of chronic lung rejection?. Eur. Respir. J. 2012;41 (1): 243-5. doi:10.1183/09031936.00103912 - Pubmed citation
- 7. Machuca JS, Niazi M, Diaz-Fuentes G. Pleuroparenchymal fibroelastosis presenting as a hypermetabolic lung nodule. J Bronchology Interv Pulmonol. 2011;18 (1): 65-8. doi:10.1097/LBR.0b013e318207b396 - Pubmed citation
- 8. von der Thüsen JH. Pleuroparenchymal Fibroelastosis: Its Pathological Characteristics. Curr Respir Med Rev. 2014;9 (4): 238-247. doi:10.2174/1573398X113096660025 - Free text at pubmed - Pubmed citation
- 9. Watanabe K, Nagata N, Kitasato Y et-al. Rapid decrease in forced vital capacity in patients with idiopathic pulmonary upper lobe fibrosis. Respir Investig. 2012;50 (3): 88-97. doi:10.1016/j.resinv.2012.06.003 - Pubmed citation
- 10. von der Thüsen JH, Hansell DM, Tominaga M et-al. Pleuroparenchymal fibroelastosis in patients with pulmonary disease secondary to bone marrow transplantation. Mod. Pathol. 2011;24 (12): 1633-9. doi:10.1038/modpathol.2011.114 - Pubmed citation
- 11. English JC, Mayo JR, Levy R, Yee J, Leslie KO. Pleuroparenchymal fibroelastosis: a rare interstitial lung disease. Respirology case reports. 3 (2): 82-4. doi:10.1002/rcr2.108 - Pubmed
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idiopathic interstitial pneumonia (mnemonic)
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