RESUMEN
The term idiopathic pleuroparenchymal fibroelastosis refers to a rare interstitial lung disease that predominantly involves the upper lobes. It has been considered a rare subtype of interstitial lung disease since 2013, when it was included in the joint consensus statement on the diagnosis of interstitial lung diseases published by the American Thoracic Society (ATS) and the European Respiratory Society (ERS). Currently, two distinct types of pleuroparenchymal fibroelastosis are recognized: the idiopathic type for cases in which it has not been possible to establish a specific etiology and a secondary type associated with a variety of different causes. The diagnosis of pleuroparenchymal fibroelastosis must be managed from a combined clinical and radiological perspective. High-resolution computed tomography (HRCT) is the imaging method of choice for the evaluation and diagnosis of pleuroparenchymal fibroelastosis. In many cases, the diagnosis will be based exclusively on the HRCT findings and histologic confirmation will be unnecessary. This article describes the clinical, radiological, and histological characteristics of pleuroparenchymal fibroelastosis, discussing the different associations with this entity and its differential diagnosis.
Asunto(s)
Neumonías Intersticiales Idiopáticas , Enfermedades Pulmonares Intersticiales , Humanos , Neumonías Intersticiales Idiopáticas/diagnóstico , Neumonías Intersticiales Idiopáticas/patología , Enfermedades Pulmonares Intersticiales/diagnóstico por imagen , Pulmón/diagnóstico por imagen , Pulmón/patología , Diagnóstico Diferencial , Tomografía Computarizada por Rayos XRESUMEN
Pleuroparenchymal fibroelastosis (PPFE) is a progressive and frequently fatal interstitial lung disease that involves the upper lobes. Although its cause remains unknown, the histopathologic evidence underlying PPFE bears striking resemblance to that of the pulmonary apical cap (PAC), a relatively common and benign entity. We describe the case of a patient with PAC that evolved into distinctly asymmetric PPFE over 6 years after unilateral surgical lung injury. Given the histologic similarity between these two conditions, we propose that these two entities underlie common biologic pathways of abnormal response to lung injury, with the presence of a PAC increasing susceptibility to the development of PPFE in the face of ongoing inflammatory insults. This case describes the histopathologic evolution of PAC to PPFE before and after an inciting injury.
Asunto(s)
Complicaciones Intraoperatorias , Enfermedades Pulmonares Intersticiales , Lesión Pulmonar , Pulmón , Fibrosis Pulmonar , Anciano , Biopsia/métodos , Caquexia/diagnóstico , Caquexia/etiología , Puente de Arteria Coronaria/efectos adversos , Diagnóstico Diferencial , Progresión de la Enfermedad , Disnea/diagnóstico , Disnea/etiología , Resultado Fatal , Humanos , Complicaciones Intraoperatorias/patología , Complicaciones Intraoperatorias/fisiopatología , Efectos Adversos a Largo Plazo/patología , Efectos Adversos a Largo Plazo/fisiopatología , Pulmón/diagnóstico por imagen , Pulmón/patología , Enfermedades Pulmonares Intersticiales/etiología , Enfermedades Pulmonares Intersticiales/patología , Enfermedades Pulmonares Intersticiales/fisiopatología , Lesión Pulmonar/complicaciones , Lesión Pulmonar/patología , Lesión Pulmonar/fisiopatología , Masculino , Fibrosis Pulmonar/etiología , Fibrosis Pulmonar/patología , Fibrosis Pulmonar/fisiopatología , Pruebas de Función Respiratoria/métodos , Tomografía Computarizada por Rayos X/métodosRESUMEN
Although pleural thickening is a common finding on routine chest X-rays, its radiological and clinical features remain poorly characterized. Our investigation of 28,727 chest X-rays obtained from annual health examinations confirmed that pleural thickening was the most common abnormal radiological finding. In most cases (92.2%), pleural thickening involved the apex of the lung, particularly on the right side; thus, it was defined as a pulmonary apical cap. Pleural thickening was more common in males than in females and in current smokers or ex-smokers than in never smokers. The prevalence increased with age, ranging from 1.8% in teenagers to 9.8% in adults aged 60 years and older. Moreover, pleural thickening was clearly associated with greater height and lower body weight and body mass index, suggesting that a tall, thin body shape may predispose to pleural thickening. These observations allowed us to speculate about the causative mechanisms of pleural thickening that are attributable to disproportionate perfusion, ventilation, or mechanical forces in the lungs.
Asunto(s)
Radiografías Pulmonares Masivas/métodos , Pleura/diagnóstico por imagen , Enfermedades Pleurales/diagnóstico por imagen , Enfermedades Pleurales/epidemiología , Tomografía Computarizada por Rayos X/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Humanos , Masculino , Radiografías Pulmonares Masivas/normas , Persona de Mediana Edad , Tomografía Computarizada por Rayos X/normas , Adulto JovenRESUMEN
AIMS: Some investigators have detected fibrinous exudate or immature organisation in the alveolar spaces prior to the development of subpleural elastofibrosis in patients with pleuroparenchymal fibroelastosis (PPFE). We hypothesised that PPFE progress is associated with an impaired lymphatic drainage system, resulting in the failed resolution of intra-alveolar exudate. The aim of this study is to investigate the pulmonary lymphatic vessels in PPFE, histologically. METHODS AND RESULTS: We retrospectively reviewed our medical records from 1995 to 2017, and selected autopsied or surgically biopsied patients with PPFE (n = 18), pulmonary apical cap (n = 18), and IPF (n = 26). We detected lymphatic endothelial cells by using immunostained specimens, calculating the percentage of lymphatic vessel area in the non-aerated area (lymphatic vessel density) and the number of lymphatic vessels per non-aerated area (per mm2 ) (lymphatic vessel number). These parameters in PPFE were compared with those in apical cap, IPF, and normal lung tissue. The lymphatic vessel density in PPFE patients [2.97%; interquartile range (IQR) 2.61-3.86] was significantly higher than that in normal lung (0.91%; IQR 0.84-1.07), pulmonary apical cap (0.67%; IQR 0.58-0.83), and IPF (0.91%; IQR 0.68-1.25) (P < 0.01 in any comparison). The lymphatic vessel number in PPFE was also significantly higher than that in normal lung, pulmonary apical cap, and IPF. Among PPFE patients, the increase in lymphatic vessel density was found to be correlated with the characteristic physiology of PPFE, such as a flattened chest cage on computed tomography and high residual volume/total lung capacity ratio on spirometry. CONCLUSIONS: Significant increase in the density and number of lymphatic vessels is a supportive characteristic that enables the differentiation of PPFE from IPF and apical cap.
Asunto(s)
Tejido Elástico/patología , Neumonías Intersticiales Idiopáticas/patología , Vasos Linfáticos/patología , Fibrosis Pulmonar/patología , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
Pathological differential diagnoses of pleuroparenchymal fibroelastosis (PPFE) include usual interstitial pneumonia (UIP) and pulmonary apical cap (PAC); however, there are no specific immunostaining makers to distinguish between these diseases. We performed immunohistochemistry using several pleural mesothelial cell-related markers, including cytokeratin-5/6, CAM5.2, WT-1, calretinin, desmin and podoplanin, for PPFE (n = 4), UIP (n = 10) and PAC (n = 3) lung sections. Among the examined markers, in PPFE and PAC lungs podoplanin commonly showed positivity for spindle cells both in thickened pleura and subpleural fibroelastosis lesions; these cells were also stained with α-smooth muscle actin, a marker of myofibroblasts. However, even in elastic fibre-rich cases, UIP lungs did not show such podoplanin-positive myofibroblasts in pleura/subpleura and fibroblastic foci. These findings were also verified using immunofluorescence. By contrast, immunohistochemically as well as morphologically, the difference between PPFE and PAC was not apparent. The presence of podoplanin-positive myofibroblasts could be a pathological hallmark of PPFE, suggesting a pathogenic process distinct from UIP but common to PAC.