Pleuroparenchymal fibroelastosis as a manifestation of chronic lung rejection?

Diagnosis of pleuroparenchymal fibroelastosis: A review

Pleuroparenchymal fibroelastosis (PPFE) is a rare lung disease with unprecedented features characterized by fibroelastotic changes in the subpleural lung parenchyma affecting the upper lobes. PPFE is usually idiopathic, but it can be caused by infection, autoimmunity, bone marrow or lung transplantation, or a genetic predisposition. Histopathologic examination of lung biopsy samples reveals homogenous subpleural fibrosis and abundant elastic fibers, allowing for a definitive diagnosis. As PPFE mimics many interstitial lung diseases, clinicians face significant difficulties in making a definitive final diagnosis. Since most disease-related comorbid conditions manifest at an advanced stage, invasive tissue sampling for histopathologic evaluation is consistently impossible. Such a patient presentation highlights the importance of an analysis based solely on clinical findings, which would provide a definitive diagnosis without the need for a biopsy. Because of its exceptional and inconceivable presentation, PPFE creates a diagnostic dilemma. In light of our two cases and the literature data, we present a diagnostic assessment score assay that relies solely on clinical manifestations without histopathological tissue verification to shed light on the diagnosis of PPFE. This review focuses on PPFE identification through the use of a diagnostic assessment analysis to improve early disease recognition without the use of invasive diagnostic interventions to obtain biopsy samples for histopathologic evaluation. This analytic approach, while not diagnostic in and of itself, may provide a useful pathway for differential diagnosis and may preclude redundant initiatives.

Pleuroparenchymal fibroelastosis

PURPOSE OF REVIEW

Pleuroparenchymal fibroelastosis (PPFE) is a clinico-radiologic-pathologic interstitial lung disease (ILD) characterized by fibrosis that has upper lobe and subpleural predominance, involving both the visceral pleura and the subjacent subpleural lung parenchyma, and comprises dense fibroelastic changes with prominent elastosis of the alveolar walls together with fibrous thickening of the visceral pleura. The goal of this review is to summarize the state-of-the-art understanding in PPFE.

RECENT FINDINGS

PPFE was described in an increasing number of conditions. The course of disease is heterogeneous. Idiopathic PPFE, cases associated with telomerase-related gene mutations, cases related to a history of chemotherapy, and cases combining PPFE with a pattern of usual interstitial pneumonia, may have a particularly poor prognosis. Well-conducted retrospective studies identified marked PPFE features in approximately 10% of patients with idiopathic pulmonary fibrosis, 11% of patients with systemic sclerosis-associated ILD, 6.5% of patients with rheumatoid arthritis-associated ILD, and 23% of patients with hypersensitivity pneumonitis. Drug therapy has not been evaluated prospectively. A small retrospective study suggests that nintedanib may slow disease progression. However, whether the efficacy of antifibrotics is comparable in PPFE and in other forms of progressive pulmonary fibrosis warrants further evaluation.

SUMMARY

Accumulating data indicate that PPFE features are associated with poor prognosis in fibrosing ILDs. Further research on the management of PPFE is warranted.

Pleuroparenchymal Fibroelastosis with a Predominantly Airway-centered Distribution: A Late Complication of Chemotherapy

Airway-centered fibroelastosis is a distinct entity characterized by prominent airway-centered elastosis of the upper lobe with little or no pleural involvement. Little is known regarding its etiology; however, it was reported to have an idiopathic or asthma-associated etiology. We document, for the first time, 2 women (19 and 60 years old) who developed pleuroparenchymal fibroelastosis with a predominantly airway-centered distribution as a late complication (6 and 9 years later, respectively) of chemotherapy. The disease rapidly progressed following the manifestation of symptoms, and they subsequently died (3 and 2 years later, respectively). Therefore, post-chemotherapy long-term monitoring for this disease is warranted.

Pleuroparenchymal fibroelastosis: Clinical, radiological and histopathological features

Pleuroparenchymal fibroelastosis (PPFE) is a rare, generally idiopathic form of interstitial pneumonia with unique clinical, radiological and histopathological features. It is named after the presence of upper lobe pleural and subjacent parenchymal fibrosis, with accompanying elastic fibers. Although it is usually an idiopathic disease, it has been linked to other co-existent diseases. Diagnostic suspicion of PPFE is based on the identification of typical abnormalities on chest CT scan, which are prevailingly located in the upper lobes, adjacent to the apex of the lungs. Diagnosis can be confirmed by histological analysis, although biopsy is not always feasible. The disease is generally progressive, but not uniformly. The course of the disease is frequently slow and involves a progressive loss of upper lobe volume, which results in platythorax, associated with a significant reduction of body mass. PPFE concomitant to other interstitial lung diseases is associated with a poorer prognosis. The disease occasionally progresses rapidly causing irreversible respiratory insufficiency, which leads to death. Currently, there is no effective pharmacological therapy available, and lung transplantation is the best therapeutic option. The purpose of this review is to draw the attention to PPFE, describe its clinical, radiological and histopathological features, analyze its diagnostic criteria, and provide an update on the management of the disease.

Assessment score for the diagnosis of a case with pleuroparenchymal fibroelastosis

Idiopathic pleuropulmonary fibroelastosis is an extremely rare lung disease characterized by the combination of fibrosis of the visceral pleura and the fibroelastotic changes transcending in the subpleural lung parenchyma that predominantly affects the upper lobes with accompanying volume loss. It is mostly idiopathic while infection, autoimmunity, bone marrow or lung transplantation and genetic predisposition may be associated with the development of PPFE. The disease is exceptionally rare as approximately ninety cases have been reported in the literature currently. A 35-year-old female presented with exertional dyspnea, dry cough and weight loss. Physical examination demonstrated platythorax, suprasternal notch deepening and fine rales over the upper lobes. Blood count, serum biochemistry, autoimmunity and serologic markers for collagen vascular diseases were within normal limits. Arterial blood gases demonstrated a low pO2 (48 mm Hg) and a high pCO2 (54 mm Hg) values. Chest x-ray showed bilateral parenchymal fibrotic lesions, left pneumothorax, bronchiectasis in the middle and pleural thickening in the upper lung zones while HRCT revealed bilateral apical pleural thickening, traction bronchiectasis, subpleural reticulations, ground-glass opacities and honeycombing in the upper lobes. Bronchoscopy, BAL cytology, smear and culture did not reveal any pathologic findings. Relevant with the clinical, laboratory, radiologic manifestations and the differential diagnosis with other interstitial lung diseases, PPFE was the final diagnosis. The aim of this case report was to present the clinical manifestations of our case. The second crucial objective was to establish a diagnostic scoring system relevant with the literature and the clinical manifestations of the patient.

Chronic Lung Allograft Dysfunction: Review of CT and Pathologic Findings

Chronic lung allograft dysfunction (CLAD) is the most common cause of mortality in lung transplant recipients after the 1st year of transplantation. CLAD has traditionally been classified into two distinct obstructive and restrictive forms: bronchiolitis obliterans syndrome and restrictive allograft syndrome. However, CLAD may manifest with a spectrum of imaging and pathologic findings and a combination of obstructive and restrictive physiologic abnormalities. Although the initial CT manifestations of CLAD may be nonspecific, the progression of findings at follow-up should signal the possibility of CLAD and may be present on imaging studies prior to the development of functional abnormalities of the lung allograft. This review encompasses the evolution of CT findings in CLAD, with emphasis on the underlying pathogenesis and pathologic condition, to enhance understanding of imaging findings. The purpose of this article is to familiarize the radiologist with the initial and follow-up CT findings of the obstructive, restrictive, and mixed forms of CLAD, for which early diagnosis and treatment may result in improved survival. Supplemental material is available for this article. © RSNA, 2021.

The similarities and differences between pleuroparenchymal fibroelastosis and idiopathic pulmonary fibrosis

The idiopathic form of pleuroparenchymal fibroelastosis (PPFE) is categorized as a rare idiopathic interstitial pneumonia in the current classification. The majority of PPFE cases are idiopathic, but many predisposing factors or comorbidities have been reported. Although histological PPFE is predominantly located in the upper lobes, which are less often affected by fibrosis in patients with idiopathic pulmonary fibrosis (IPF), the clinical course of PPFE is seemingly similar to that of IPF. However, upper lobe fibroelastosis has various clinical and physiological characteristics that differ from those of IPF, including a flattened thoracic cage and a marked decrease in the forced vital capacity (FVC) but with a preserved residual volume. Compared with IPF, the decrease in the walking distance is mild despite the markedly decreased FVC in PPFE, and chest radiograph more frequently shows the elevation of bilateral hilar opacities with or without tracheal deviation. The prognosis may be related to the development of fibrosing interstitial pneumonia in the lower lobes with elevated levels of serum Krebs von den Lungen-6; however, there is marked variation in the pathogenesis and clinical features in PPFE. A proposal of the diagnostic criteria for idiopathic PPFE with and without surgical lung biopsy, which has recently been published, may be useful.

Suspected pleuroparenchymal fibroelastosis relapse after lung transplantation: a case report and literature review

Pleuroparenchymal fibroelastosis (PPFE) is a very rare lung disease characterized by dense fibrous thickening of the visceral pleura and intraalveolar fibrosis containing prominent elastosis, with typical upper lobe predominance. PPFE usually shows progressive restrictive ventilatory impairment refractory to medical treatment; bilateral lung transplantation currently remains the only available therapeutic option. In this report, we describe a case of suspected PPFE relapse after lung transplantation that, to our knowledge, has never been described in the medical literature.

A 48-year-old male with idiopathic pleuroparenchymal fibroelastosis underwent a bilateral lung transplant in our department. 8 months later, he presented with progressively worsening clinical condition, his respiratory state gradually deteriorated. High-resolution CT again showed bilateral diffused parenchymal consolidations, with prevalence in the upper lobes and subpleural regions. A PPFE relapse was therefore suspected, so he was listed for lung retransplantation, which was performed ten months after the first transplant. Histopathological analysis of the second explanted lung again confirmed the diagnosis of PPFE. The case highlights the possibility of PPFE relapse after lung transplantation, that may add to the increasing evidence of an underlying auto-immune mechanism contributing to its pathogenesis.

Criteria for the diagnosis of idiopathic pleuroparenchymal fibroelastosis: A proposal

BACKGROUND

Physicians have few opportunities to perform surgical lung biopsy (SLB) to diagnose idiopathic pleuroparenchymal fibroelastosis (IPPFE). Therefore, diagnostic criteria for IPPFE that do not require SLB must be established. Herein, we propose diagnostic criteria for IPPFE with and without SLB.

METHODS AND RESULTS

The diagnostic criteria for IPPFE with SLB are histological, based on computed tomography (CT) lesions compatible with PPFE, predominantly in the upper lobes. The three diagnostic criteria for IPPFE without SLB are as follows: (1) radiologically possible IPPFE (a radiological criterion confirming CT lesions in both lung apexes, regardless of the lower lobe lesions); (2) radiologically probable IPPFE (also a radiological criterion, but mandatory to confirm chest radiograph findings of bilateral upward shift of the hilar structures and/or CT findings of volume loss of the upper lobes); (3) radiologically and physiologically probable IPPFE. Our data from 41 patients with IPPFE and 97 with idiopathic pulmonary fibrosis (IPF) showed that the percentage of the predicted values of the ratio of residual volume to total lung capacity (RV/TLC %pred.) ≥115% and body mass index (BMI) ≤20 kg/m² plus RV/TLC %pred. ≥80% performed well for discriminating IPPFE from IPF. These parameters were thus added to criterion (3).

CONCLUSIONS

We have proposed diagnostic criteria for IPPFE in patients with and without SLB. Both imaging criteria and physiological criteria using RV/TLC and BMI successfully discriminate IPPFE from chronic IIPs when SLB cannot be performed.

Cause of pleuroparenchymal fibroelastosis following allogeneic hematopoietic stem cell transplantation

Late-onset noninfectious pulmonary complications (LONIPCs) are life-threatening complications after hematopoietic stem cell transplantation (HSCT). Pleuroparenchymal fibroelastosis (PPFE) is a LONIPC, but its etiology remains elusive. Chronic graft-versus-host disease (cGVHD) and alkylating agents used for conditioning have been considered possible causes of PPFE. Therefore, to investigate the primary cause of PPFE in allogeneic HSCT, we compared three secondary PPFE groups, namely, the post-lung-transplantation, post-autologous-HSCT or chemotherapy-alone, and post-allogeneic-HSCT groups, and focused on the coexistence of bronchiolitis obliterans (BO), a typical phenotype of cGVHD. We found a trend towards higher rates of PPFE with BO in the post-allogeneic-HSCT and post-lung-transplantation groups (71% and 90%, respectively) than in the post-autologous-HSCT or chemotherapy-alone group (25%). The incidence of BO following allogeneic HSCT is reportedly <10%. If PPFE in the post-allogeneic-HSCT group has no association with BO and is induced by alkylating agents rather than cGVHD, the incidence of BO in PPFE in this group is estimated to be <10%, which is inconsistent with our data (71%). Thus, this study suggests that PPFE following allogeneic HSCT could be mainly induced by cGVHD because the majority of cases are associated with BO, a typical phenotype of cGVHD.

Pleuroparenchymal fibroelastosis (PPFE) treated with lung transplantation and review of the literature

A 26-year-old woman presented with a 15-year history of non-progressive dyspnoea. Chest imaging showed bilateral apical pleural and parenchymal scarring, pleural thickening and bronchiectasis. Pulmonary function tests showed a moderate restrictive defect. Non-invasive workup was non-revealing; therefore, the patient was referred for video-assisted thoracic surgery and lung biopsy. Histopathology revealed pleural thickening and, subpleural parenchymal fibrosis and elastic tissue deposition. Lung parenchyma further away from the pleura was well preserved. Based on these findings, the patient was diagnosed with pleuroparenchymal fibroelastosis (PPFE). Since PPFE is a progressive disorder without effective medical therapies, and given our patient's worsening symptoms, she underwent bilateral lung transplantation. It has been almost 4 years since the lung transplantation, our patient continues to do well. To the best of our knowledge, to date, this is the longest follow-up reported for a PPFE patient undergoing lung transplantation.

The upward shift of hilar structures and tracheal deviation in pleuroparenchymal fibroelastosis

The upward shift of hilar structures is a characteristic finding on chest radiographs in pleuroparenchymal fibroelastosis (PPFE). However, the relationship between the hilar shift and clinical parameters is unclear. In this study, the ratio of the length of the lung apex to the hilum and the length of the apex to the base of the right lung was measured using chest computed tomography (CT) at the time of the diagnosis, and the relationship with clinical parameters was investigated. We also examined the deviations of the trachea on chest radiographs and compared them with those in idiopathic pulmonary fibrosis (IPF) and early-stage lung cancer. Thirty-eight PPFE patients in a previous study included 20 patients who simultaneously showed the lower lobe lesions. The median ratio of the length of the apex to the hilum/apex to the base was 0.32 (range: 0.10–0.41) in PPFE, and this value was significantly lower than that in IPF (0.39; 0.32–0.45, n = 38) and in lung cancer (0.41; 0.33 to 0.45, n = 38) (p < 0.001, respectively). However, the ratio of the length of the apex to the hilum/apex to the base did not correlate with the dyspnea scale, body mass index or pulmonary function in PPFE. Tracheal deviations were observed in 41 out of 52 PPFE patients (36 with rightward deviations, 5 with leftward deviations) and in 30 out of 52 IPF patients (30 with rightward deviations) (p = 0.01). Although the existence of the upward shift of hilar structures on chest images might lead to a diagnosis of PPFE, the extent of hilar elevation does not necessarily reflect disease progression. Tracheal deviation is not a specific finding for PPFE.

Pleuroparenchymal fibroelastosis secondary to autologous hematopoietic stem cell transplantation: A case report

Pleuroparenchymal fibroelastosis (PPFE) is a rare interstitial lung disease. Although an increased number of PPFE cases have been reported recently, the characteristics of this condition have not been well described. The present study reports on the case of a 34-year-old male patient who presented with unilateral lung abnormalities. The patient was admitted due to a 9-year history of progressive cough and exertional dyspnea, as well as a history of Hodgkin's lymphoma treated by autologous hematopoietic stem cell transplantation (HSCT). The patient had been initially diagnosed with tuberculosis and received regular anti-tuberculosis therapy for 18 months; however, the symptoms progressed. Serial chest computed tomography scans indicated a gradually worsening diffuse pleural thickening, dense subpleural opacification and volume loss, associated with evidence of fibrosis in the right lung. On physical examination the patient was cachectic, with a body mass index of 18.5 kg/m², and he had a flattened thoracic cage. Arterial blood gas analysis revealed hypoxia. Pulmonary function tests revealed restrictive ventilation dysfunction and decreased diffusion capacity. The microbiological and cytological examinations were negative. Lung biopsy revealed a thickened pleura consisting of large amounts of collagen and elastic fibers, coexisting with subpleural intra-alveolar fibrosis with alveolar septal elastosis, without inflammatory infiltrates. The patient was diagnosed with PPFE secondary to HSCT and eventually succumbed to respiratory failure and infection while waiting for a lung transplant. Physicians should be aware of the typical and atypical characteristics of this rare disease, as its clinical and radiological characteristics may lead to misdiagnosis, particularly as chronic infections. The prognosis remains poor without effective long-term treatment.

Cryobiopsies are diagnostic in Pleuroparenchymal and Airway-centered Fibroelastosis

BACKGROUND

Idiopathic pulmonary fibroelastosis (iPPFE) is a rare lung lesion characterized by pleural and subpleural parenchymal thickening due to accumulation of fibroelastotic tissue. Only recently, a few cases with a peribronchiolar distribution of fibroelastotic tissue have been reported. These lesions are more prominent in the upper lobes. Even though high resolution computed tomography (HRCT) scan features are considered characteristic, a histological confirmation is suggested, mainly when the clinical setting is not clearly defined. However, due to non-negligible complications, a surgical lung biopsy is not often recommended. The prognosis is usually poor and currently, the only effective treatment is lung transplantation.

METHOD

Patients with a multidisciplinary diagnosis of iPPFE or airway-centered fibroelastosis (airway-centered FE), with histological confirmation by transbronchial cryobiopsy, were identified from an ongoing interstitial lung disease registry. Data on patient demographics, HRCT patterns, size and number of biopsies, histology patterns and complications were registered.

RESULTS

Seven patients were diagnosed with iPPFE and one patient was diagnosed with airway-centered FE. Pneumothorax was documented in three cases, but none of them required a chest tube. No other complications during or after the procedure were observed.

CONCLUSION

This study suggests that using cryobiopsies in the diagnostics of PPFE and airway-centered FE is safe and effective.

Lung Transplantation as Successful Treatment of End-stage Idiopathic Pleuroparenchymal Fibroelastosis: A Case Report

Pleuroparenchymal fibroelastosis (PPFE) is a rare condition, characterized by predominantly upper-lobe pleural and subjacent parenchymal fibrosis, the latter being intra-alveolar with accompanying elastosis of the alveolar walls that leads a clinical progression to respiratory failure. This condition may not be as rare as it seems to be, because nowadays the increasing awareness among specialists is raising the number of new diagnoses. Limited data are available about the prognosis, both for secondary and idiopathic forms. Nevertheless, the idiopathic form seems to be rapidly progressive and no treatment can control the disease, which is why management is challenging. Since the disease was characterized, PPFE cases have been reported in the literature, but most have been secondary rather than idiopathic. Of these, few have successfully undergone lung transplantation as a treatment of end-stage respiratory failure. We here report a successful case of a 38-year-old man affected by idiopathic PPFE who underwent bilateral lung transplantation after extracorporeal membrane oxygenation bridging for an abrupt transition to critical clinical conditions. After a complex postoperative course and a first year characterized by acute rejection, the patient is alive at 5 years with a good quality of life. Our experience confirms that lung transplantation would be a valuable treatment option in case of end-stage idiopathic PPFE cases.

Pleuroparenchymal fibroelastosis diagnosed by multidisciplinary discussions in Japan

BACKGROUND

Pleuroparenchymal fibroelastosis (PPFE) is a rare subset of idiopathic interstitial pneumonias. No large-scale clinical studies of PPFE have been published. The aim of the study was to clarify the clinical and physiological characteristics of PPFE in Japan METHODS: This was a retrospective, nationwide, and multicenter study in Japan. We reviewed 52 patients with PPFE, diagnosed after multidisciplinary discussions.

RESULTS

Flat chest index, defined as the ratio of anteroposterior diameter to transverse diameter of thoracic cage at the level of 6th thoracic vertebra, correlated positively with body mass index (BMI) (r = 0.340, p = 0.013) and percentage of predicted value of forced vital capacity (FVC %pred) (r = 0.355, p = 0.012), and negatively with the ratio of residual volume to total lung capacity (RV/TLC) (r = -0.312, p = 0.042). RV/TLC correlated negatively with BMI (r = -0.746, p < 0.0001) and FVC %pred (r = -0.507, p = 0.0005), and positively with age, and physiological variables (GAP) scores (r = 0.332, p = 0.030). The median survival time and the cumulative 5-year survival rate were 96 months and 58%, respectively. Patients with KL-6 level >600 (U/mL) survived shorter than those with <600 (p < 0.001).

CONCLUSION

Low BMI, decreased FVC and increased RV/TLC in PPFE may be related to the progression of flattened chest cage which impairs distension of chest cage at inspiration. Elevated serum levels of KL-6 suggest a poor prognosis of PPFE.

Is hypothyroidism in idiopathic pleuroparenchymal fibroelastosis a novel lung-thyroid syndrome?

BACKGROUND

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare type of interstitial pneumonia characterized by fibroelastosis. Patients with IPPFE as well as idiopathic interstitial pneumonia often have autoimmune diseases, which sometimes coincide with hypothyroidism (HypoT). However, there have been no reports on the association between IPPFE and HypoT. The purpose of this study was to evaluate the correlation between IPPFE and HypoT. We also examined the pathological features of the thyroid glands from autopsied cases.

METHODS

Thirteen patients diagnosed with IPPFE from among 255 consecutive cases of idiopathic interstitial pneumonia were included in this study; pertinent data were obtained from our hospital's clinical library. We examined the prevalence of HypoT and compared the clinical, radiological, and pathological features between the patients with and those without HypoT. Histological analyses of the lungs and thyroid glands were performed in 4 and 3 cases, respectively.

RESULTS

HypoT was identified in 7 of 13 patients (53.8%). Sex, body mass index, survival time, and laboratory test results were not significantly different between patients with and those without HypoT. Radiological and pathological lung findings were similar between both groups of patients. Thyroid gland histology demonstrated perifollicular or interlobular fibrosis without inflammation in all three cases, including a euthyroid case.

CONCLUSIONS

Although we only analyzed a small number of IPPFE cases, HypoT was prevalent among all of them. Characteristic fibrosis in the thyroid gland was observed even in a euthyroid case. Therefore, patients with IPPFE may potentially have thyroid gland dysfunction through a common pathogenesis in both organs.

Pleuroparenchymal Fibroelastosis: A Review of Histopathologic Features and the Relationship Between Histologic Parameters and Survival

Pleuroparenchymal fibroelastosis (PPFE) is now a defined clinicopathologic entity in the updated 2013 ATS/ERS classification of idiopathic interstitial pneumonias (IIPs), which has led to a significant increase in cases being diagnosed at our institution. We have therefore reviewed 43 PPFE cases (58 biopsies in total) to assess whether any clinical or histopathologic features provide prognostic information. A semiquantatitive grading system was used to assess extent of fibroblastic foci, intra-alveolar fibroelastosis, visceral pleural fibrosis, chronic inflammation in areas of fibrosis, vascular fibrointimal thickening, and presence of granulomas. Other patterns of interstitial lung disease were also noted, if present. All biopsies showed intra-alveolar fibroelastosis, fibroblastic foci at the leading edge of fibrosis and chronic inflammation within areas of fibrosis, 91% showed vascular fibrointimal thickening of vessels, 73% showed pleural fibrosis, and 35% showed granulomas. Ten cases showed a coexistent IIP (5 showed usual interstitial pneumonia, 5 showed features of hypersensitivity pneumonitis). There was no significant correlation with mortality and severity of histologic parameters, other than a significant decrease in mortality in PPFE with coexistent granulomas, after adjusting for age and gender (hazard ratio, 0.27; P=0.049). Male gender was also associated with an increased risk of mortality, after adjusting for age (hazard ratio, 4.8; P=0.045). PPFE is more common than previously thought, not infrequently showing coexistent pathology, specifically usual interstitial pneumonia and granulomatous lung disease, our data suggesting the latter may have prognostic significance.

Pleuroparenchymal Fibroelastosis With Long History of Asbestos and Silicon Exposure

Pleuroparenchymal fibroelastosis (PPFE) is an uncommon interstitial lung disease. PPFE is characterized by fibroelastosis involving the pleura and subjacent parenchyma with a predominantly upper lobe distribution. While different possible environmental and familial etiologies have been postulated in the literature, the etiology of this disease remains essentially unclear and most cases are considered as idiopathic. In this report, we describe a rare case of PPFE with multiple lung lobe involvements and prolonged asbestos and silica exposure. Our goal is to investigate the exposure of asbestos and silica and try to identify their possible association with PPFE.

Pleuroparenchymal Fibroelastosis of the Lung: A Review

Described in Japan by Amitani et al in 1992, the entity of idiopathic upper lobe fibrosis was subsequently given the name pleuroparenchymal fibroelastosis (PPFE) in the English-speaking world. Pleuroparenchymal fibroelastosis is believed to be a rare disease characterized by a fibrosing process affecting the pleura and the subpleural lung parenchyma, with a predilection for the upper lobes. Uniquely, the fibrosing process is elastotic in nature, being associated with intra-alveolar fibrosis. The etiology of PPFE is unclear at this juncture, with many cases being considered as idiopathic forms of the disease. Conditions associated with PPFE include infections, bone marrow transplantation, and autoimmunity. In this review, we explore the clinical, radiologic, and pathologic features associated with PPFE in light of current understanding of the disease. Recent studies implicated that PPFE may not be as uncommon as claimed. The various differential diagnoses and implications of diagnosing PPFE are discussed.

Pleuroparenchymal fibroelastosis: report of two cases in Brazil

Pleuroparenchymal fibroelastosis (PPFE) is a rare lung disease. It can be idiopathic or associated with any one of various conditions. To our knowledge, this is the first report of two cases of PPFE in Brazil. Our first patient presented with pleural and subpleural fibrosis in the upper lobes; a spiculated nodule in the left upper lobe; and a mild reticular pattern in the lower lobes. Surgical lung biopsy revealed PPFE in the upper lobes, including the nodule, and unclassified interstitial pneumonia in the left lower lobe. Our second patient had a history of exposure to domestic birds, indicating a risk of hypersensitivity pneumonitis, and presented with advanced lung disease, predominantly in the upper lobes, together with subpleural fibrosis.That patient underwent lung transplantation. In the explant specimen, PPFE and granulomas were identified, suggesting hypersensitivity pneumonitis as an associated cause.

Chronic Cough and Bilateral Pneumothoraces in a Nonsmoker

An 82-year-old Japanese nonsmoking man presented with persistent dry cough and small left apical pneumothorax. High resolution CT scan of the chest demonstrated bilateral upper lobe pleuroparenchymal thickening and architectural distortion. Serial imaging revealed mild progression and development of small bilateral pneumothoraces, and pneumomediastinum. A surgical lung biopsy was required to confirm the diagnosis.

Heterogeneous clinical features in patients with pulmonary fibrosis showing histology of pleuroparenchymal fibroelastosis

BACKGROUND

The histological pattern of pleuroparenchymal fibroelastosis (PPFE) is well defined, but its clinical features remain unclear.

METHODS

We retrospectively examined the predominantly involved lung-fields (based on abnormal opacities on computed tomography [CT] images), and the initial value and annual decline of respiratory function in patients with pulmonary fibrosis presenting with histologically confirmed PPFE.

RESULTS

Thirteen female and nine male subjects were included. Eleven interpreters independently analyzed 231 CT image series. One-third of the CT series (78/231) was interpreted as demonstrating equal involvement of the upper and lower lung fields, i.e., six out of 21 patients had equal involvement of the upper and lower lung fields, based on a majority decision of the interpreters. The residual volume/total lung capacity (RV/TLC) was increased and correlated inversely with forced vital capacity (FVC) at the initial measurement. FVC followed two patterns of decline over time: a gradual decline over a follow-up period of more than 6 years (-55mL/year, R(2)=0.799), and a relatively rapid decline over a shorter period (-364mL/year, R(2)=0.855) as determined by mixed-effect linear regression.

CONCLUSIONS

The predominantly involved sites seen on CT images of PPFE were not limited to the upper lobes. In some cases, upper lung fields were predominantly involved, but in other cases, both upper and lower lung fields were equally involved. Two patterns of FVC decline exists: a rapid decline over a short period and a slow decline over a longer period, suggesting that the disease follows a heterogeneous clinical course.

Idiopathic pleuroparenchymal fibroelastosis, a new idiopathic interstitial pneumonia: A case report

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare disease, idiopathic in most of the cases described in the literature. We report the case of a 55-year-old patient, non-smoker with tuberculosis treated in his youth, starting with progressive dyspnoea and cough, with radiographic abnormalities consisting of pleural thickening, bronchiectasis and structural distortion predominantly in the upper lobes. Due to functional impairment and persistent radiographic abnormalities, biopsy by video-assisted thoracoscopic surgical was decided. The presence of striking elastosis, absence of interstitial damage and abrupt boundary of the fibrous lesion with healthy lung allowed the diagnosis of IPPFE. Currently, the patient has no specific treatment and is in follow-up in the Transplant Unit.

Pleuroparenchymal fibroelastosis: role of high-resolution computed tomography (HRCT) and CT-guided transthoracic core lung biopsy

Objectives

Pleuroparenchymal fibroelastosis (PPFE) is a rare idiopathic interstitial pneumonia (IIP) with variable clinical and radiological features. Diagnosis is based on histology obtained by surgical lung biopsy, which is associated with significant mortality and morbidity. This study aims to briefly review PPFE and discuss the role of CT-guided transthoracic core lung biopsy (TTB) in its diagnosis.

Materials/Methods

Four cases of PPFE diagnosed at our institution with TTB are reported and discussed.

Results

Clinical, radiological and histological features are in agreement with the previous literature cases. TTB provided the diagnosis in all cases. Iatrogenic pneumothorax was the main complication in all patients. Placement of a chest tube was needed in three patients. An overlap between PPFE and other interstitial lung diseases (ILD) was documented.

Conclusion

PPFE is an underdiagnosed IIP, so radiologist awareness of it needs to be widespread in patients with fibrosis with apical-caudal distribution. Coexistence of different lung diseases strengthens the idea of a predisposing factor. TTB proved to be a good diagnostic tool and can be considered the first choice for invasive assessment of these patients. PFFE has a variable course with no established therapeutic options; therefore a multidisciplinary team is crucial in the approach to patients with ILD.

Main messages/Teaching Points

• PPFE should be considered in the differential diagnosis of fibrosis with apical-caudal distribution.

• CT-guided TTB can be considered the first choice for invasive assessment of PPFE.

• Site of biopsy has to be chosen carefully in order not to miss PPFE.

• Coexistence of different lung diseases strengthens the idea of a predisposing factor.

• A multidisciplinary team is crucial in the approach to patients with ILD.

Idiopathic pleuroparenchymal fibroelastosis: a rare but increasingly recognized entity

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a recently described rare entity, characterized by pleural and subpleural parenchymal fibrosis and elastosis mainly in the upper lobes. The etiology and pathophysiology are unknown. The prognosis is poor, with no effective therapies other than lung transplantation. IPPFE should be properly identified so that it can be approached correctly. This report describes two clinical cases with clinical imaging and histological features compatible with IPPFE.

Histological evolution of pleuroparenchymal fibroelastosis

AIMS

To investigate the histological evolution in the development of pleuroparenchymal fibroelastosis (PPFE).

METHODS AND RESULTS

We examined four patients who had undergone surgical lung biopsy twice, or who had undergone surgical lung biopsy and had been autopsied, and in whom the histological diagnosis of the first biopsy was not PPFE, but the diagnosis of the second biopsy or of the autopsy was PPFE. The histological patterns of the first biopsy were cellular and fibrotic interstitial pneumonia, cellular interstitial pneumonia (CIP) with organizing pneumonia, CIP with granulomas and acute lung injury in cases 1, 2, 3, and 4, respectively. Septal elastosis was already present in the non-specific interstitial pneumonia-like histology of case 1, but a few additional years were necessary to reach consolidated subpleural fibroelastosis. In case 3, subpleural fibroelastosis was already present in the first biopsy, but only to a small extent. Twelve years later, it was replaced by a long band of fibroelastosis. The septal inflammation and fibrosis and airspace organization observed in the first biopsies were replaced by less cellular subpleural fibroelastosis within 3-12 years.

CONCLUSIONS

Interstitial inflammation or acute lung injury may be an initial step in the development of PPFE.

WITHDRAWN: Idiopathic pleuroparenchymal fibroelastosis: A rare but increasingly recognized entity

This article has been withdrawn for editorial reasons because the journal will be published only in English. In order to avoid duplicated records, this article can be found at http://dx.doi.org/10.1016/j.rppnen.2014.04.008. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Quantitative analysis of lung elastic fibers in idiopathic pleuroparenchymal fibroelastosis (IPPFE): comparison of clinical, radiological, and pathological findings with those of idiopathic pulmonary fibrosis (IPF)

Background

The pathological appearance of idiopathic pleuroparenchymal fibroelastosis (IPPFE) with hematoxylin-eosin staining is similar to that of usual interstitial pneumonia (UIP) in patients with idiopathic pulmonary fibrosis (IPF). The amount of elastic fibers (EF) and detailed differences between IPPFE and IPF have not been fully elucidated. The aim of this study was to quantify the EF and identify the differences between IPPFE and IPF.

Methods

We evaluated six patients with IPPFE and 28 patients with IPF who underwent surgical lung biopsy or autopsy. The patients’ clinical history, physical findings, chest high-resolution computed tomography (HRCT) findings, and pathological features of lung specimens were retrospectively evaluated. The amounts of EF in lung specimens were quantified with Weigert’s staining using a camera with a charge-coupled device and analytic software in both groups.

Results

Fewer patients with IPPFE than IPF had fine crackles (50.0% vs. 96.4%, p = 0.012). Patients with IPPFE had a lower forced vital capacity (62.7 ± 10.9% vs. 88.6 ± 21.9% predicted, p = 0.009), higher consolidation scores on HRCT (1.7 ± 0.8 vs. 0.3 ± 0.5, p < 0.0001), lower body mass indices (17.9 ± 0.9 vs. 24.3 ± 2.8, p < 0.0001), and more pneumothoraces than did patients with IPF (66.7 vs. 3.6%, p = 0.002). Lung specimens from patients with IPPFE had more than twice the amount of EF than did those from patients with IPF (28.5 ± 3.3% vs. 12.1 ± 4.4%, p < 0.0001). The amount of EF in the lower lobes was significantly lower than that in the upper lobes, even in the same patient with IPPFE (23.6 ± 2.4% vs. 32.4 ± 5.5%, p = 0.048). However, the amount of EF in the lower lobes of patients with IPPFE was still higher than that of patients with IPF (23.6 ± 2.4% vs. 12.2 ± 4.4%, p < 0.0001).

Conclusion

More than twice the amount of EF was found in patients with IPPFE than in those with IPF. Even in the lower lobes, the amount of EF was higher in patients with IPPFE than in those with IPF, although the distribution of lung EF was heterogeneous in IPPFE specimens.

Pleuroparenchymal Fibroelastosis: Its Pathological Characteristics

Pleuroparenchymal fibroelastosis (PPFE) is a distinct pattern of pulmonary fibrosis which often runs a rapidly progressive course with a poor prognosis, and it is likely to be introduced as a separate entity in the new classification scheme of idiopathic interstitial pneumonias. It is characterised by pleural fibrosis and subpleural fibroelastosis, with an upper lobe predominance. In addition to cases following lung and bone marrow transplantation, familial and idiopathic cases have been described. The literature on PPFE is fragmented, however, and primarily consists of small case series, lacking a uniform methodology of clinical, radiological and histopathological description. In this review article, most previously published reports of PPFE in the English-language literature will be discussed and the salient clinical and histopathological data analysed to arrive at a working definition of PPFE in daily histopathological practice, and to aid the generation of a unifying hypothesis regarding its potential aetiologies and pathogenesis.

Pleuroparenchymal Fibroelastosis: Its Clinical Characteristics

Pleuroparenchymal fibroelastosis (PPFE) is a rare pulmonary fibrosis that is clinically characterized by upperlobe predominant fibrosis. PPFE is a slowly progressive disorder and its first symptom is dyspnea or dry cough. Chest pain because of pneumothorax may be the first symptom in some patients. Patients with PPFE are slender with a flat rib cage or abnormally narrowed anterior-posterior thoracic dimension. Decreases in forced vital capacity, total lung capacity, and diffusing capacity are respiratory-function characteristics of PPFE, similar to those seen in idiopathic pulmonary fibrosis (IPF). The most remarkable difference in clinical features between PPFE and IPF is imaging findings, with upper-lobe-predominant lesions in PPFE and lower-lobe-predominant lesions in IPF.