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

Proposed Clinical Algorithm for Pleuroparenchymal Fibroelastosis (PPFE)

Pleuroparenchymal fibroelastosis (PPFE) is characterized by fibrosis involving the pleura and subpleural lung parenchyma, predominantly in the upper lobes. As PPFE appears to occur in patients with heterogeneous etiologies, the disease course is thus also heterogenous, with some patients showing rapid progression while others have slow progression. Therefore, it is very difficult to predict prognosis with PPFE. Needless to say, this problematic matter has influenced the treatment strategy of PPFE patients. In fact, until now no evidence has been shown for use in creating an appropriate management algorithm for PPFE. We speculate that "uncoordinated breathing" is the most important reason for dyspnea in PPFE patients. Because monitoring of physique and not just pulmonary function and radiological evaluation is also very important, particularly in PPFE patients, this review focused on the characteristics of PPFE through an overview of previous studies in this field, and we proposed an algorithm as precision medicine based on the current evidence. Multiple views by the pulmonologist are needed to standardize a clinical algorithm that is necessary to correctly assess PPFE patients under the premise of maintenance of physique by providing appropriate nutritional care and pulmonary rehabilitation.

Platythorax progresses with lung involvement in pleuroparenchymal fibroelastosis

BACKGROUND

Patients diagnosed with pleuroparenchymal fibroelastosis (PPFE) exhibit unique clinical features, including upper lobe-dominant lung involvement and platythorax (or flattened thoracic cage). Although platythorax have been shown to be a sign of disease progression, the temporal relationship between the progression of platythorax and the extent of lung involvement has not been closely investigated.

METHODS

We retrospectively investigated patients diagnosed with PPFE, who did not exhibit fibrotic lesions other than PPFE in the lower lobes. We estimated the fibrosis score, which is a visual score indicating the percentage of lung parenchyma occupied by the disease on computed tomography images selected every 2 cm from the lung apex to the lung base, and the flat chest index (the ratio of the anteroposterior diameter of the thoracic cage to the transverse diameter of the thoracic cage). Additionally, we investigated serial changes in the flat chest index and fibrosis score.

RESULTS

A total of 29 patients were included in this study. The fibrosis score was found to be weakly and inversely correlated with forced vital capacity %predicted at the diagnosis (r = -0.40, p = 0.038). Furthermore, the annual changes in the flat chest index and fibrosis score was found to be moderately and inversely correlated (r = -0.663, p = 0.0037).

CONCLUSIONS

These results indicate that there is a causal relationship between the progression of fibroelastosis and that of platythorax in patients with PPFE.

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.

Severe and progressive platythorax disproportionate to lung fibrosis: A rare variant of idiopathic pleuroparenchymal fibroelastosis

A 57-year-old man was referred to our department because of progressive shortness of breath and emaciation. He had experienced pneumothorax three times in the past five years. The patient radiologically showed mild upper-lobe predominant airspace consolidation and severe platythorax and was clinically diagnosed with idiopathic pleuroparenchymal fibroelastosis (PPFE). Although the wedge-shaped shadows in the bilateral lung apexes did not significantly progress, his platythorax gradually worsened during the clinical course. He ultimately died of chronic respiratory failure 1.2 years after the diagnosis. This case demonstrates a rare variant of idiopathic PPFE with progressive platythorax disproportionate to the extent of upper-lobe fibroelastosis.

The pathogenesis and pathology of idiopathic pleuroparenchymal fibroelastosis

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare subtype of idiopathic interstitial pneumonias that consists of elastofibrosis involving the lung parenchyma and pleural collagenous fibrosis predominantly located in the upper lobes. IPPFE has various distinct clinical and physiological characteristics, including platythorax and a marked decrease of forced vital capacity with an increased residual volume on a respiratory function test. The concept of IPPFE is now widely recognized and some diagnostic criteria have been proposed. In addition, the accumulation of cases has revealed the pathological features of IPPFE. However, little is known about the pathogenesis or the process of disease formation in IPPFE. This review article will provide a summary of the pathological features and previously reported hypotheses on disease formation in IPPFE, to discuss the potential etiologies and pathogenesis of IPPFE.

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.

Chronic Progressive Dyspnea in a 71-Year-Old Man: A Diagnostic Ithaca After 8 Years of Consultation

CASE PRESENTATION

A 71-year-old ex-bus driver (ex-smoker, 20 pack-years) was admitted for the first time to the respiratory department because of chronic dry cough and progressive exertional dyspnea with insidious onset 8 years ago. The patient also reported weight loss of about 20 kg in 3 years and proximal muscle weakness. A decade ago, he was diagnosed with gastric adenocarcinoma and subjected to partial gastrectomy and splenectomy, followed by an unspecified chemotherapy regimen. Additionally, the patient has coronary disease and underwent coronary bypass graft surgery 7 years ago. In the course of his disease, many diagnostic procedures have been performed including Mantoux tests, five CT scans, a CT-guided biopsy, two bronchoscopies, and an 18F-fluorodeoxyglucose PET scan with inconclusive results. The patient was referred to the hospital to have his long-lasting condition diagnosed and treated.