A Case of Rosai-Dorfman Disease Presenting as an Isolated Pleural Plaque.

Rosai-Dorfman disease (RDD) is a rare non-Langerhans histiocytic disorder primarily involving lymph nodes. Extranodal RDD has a heterogenous presentation, and isolated pulmonary involvement is rare. We report the only case of RDD presenting as an isolated pleural mass. Our patient was a 55-year-old female with multiple comorbidities who presented with chest pain. Imaging revealed an enlarging pleural-based lesion. She underwent resection of the pleural mass, showing an atypical histiocytic infiltrate in a prominent background of collagenous fibrosis. Immunohistochemistry shows CD1a-negative and S100-positive atypical histiocytic cells demonstrating emperipolesis, confirming the diagnosis of RDD. She is currently on six-month CT surveillance with no recurrence of the disease. This case highlights the unique pulmonary presentation of RDD. It also underscores that observations may be appropriate in isolated asymptomatic pleural involvement cases.

Does previous asbestos exposure increase the risk of a post coronary artery bypass graft (CABG) pleural effusion - a routine data study?

BACKGROUND: Development of pleural effusion (PE) following CABG is common. Post-CABG PE are divided into early- (within 30 days of surgery) and delayed-onset (30 days-1 year) which are likely due to distinct pathological processes. Some experts suggest asbestos exposure may confer an independent risk for late-onset post-CABG PE, however no large studies have explored this potential association. RESEARCH QUESTION: To explore possible association between asbestos exposure and post-CABG PE using routine data. METHODS: All patients who underwent CABG 01/04/2013-31/03/2018 were identified from the Hospital Episode Statistics (HES) Database. This England-wide population was evaluated for evidence of asbestos exposure, pleural plaques or asbestosis and a diagnosis of PE or PE-related procedure from 30 days to 1 year post-CABG. Patients with evidence of PE three months prior to CABG were excluded, as were patients with a new mesothelioma diagnosis. RESULTS: 68,150 patients were identified, of whom 1,003 (1%) were asbestos exposed and 2,377 (3%) developed late-onset PE. After adjusting for demographic data, Index of Multiple Deprivation and Charlson Co-morbidity Index, asbestos exposed patients had increased odds of PE diagnosis or related procedure such as thoracentesis or drainage (OR 1.35, 95% CI 1.03-1.76, p = 0.04). In those with evidence of PE requiring procedure alone, the adjusted OR was 1.66 (95% CI 1.14-2.40, p = 0.01). Additional subgroup analysis of the 518 patients coded for pleural plaques and asbestosis alone revealed an adjusted OR of post-CABG PE requiring a procedure of 2.16 (95% CI 1.38-3.37, p = 0.002). INTERPRETATION: This large-scale study demonstrates prior asbestos exposure is associated with modestly increased risk of post-CABG PE development. The risk association appears higher in patients with assigned clinical codes indicative of radiological evidence of asbestos exposure (pleural plaques or asbestosis). This association may fit with a possible inflammatory co-pathogenesis, with asbestos exposure 'priming' the pleura resulting in greater propensity for PE evolution following the physiological insult of CABG surgery. Further work, including prospective studies and clinicopathological correlation are suggested to explore this further.

Lung cancer and mesothelioma risks in a prospective cohort of workers with asbestos-related lung or pleural diseases.

BACKGROUND: Asbestos causes mesothelioma and lung cancer. In the European Union, asbestos was banned in 2005, but it is still in use in many other countries. The aim of this study was to estimate the lung cancer and mesothelioma incidence risk of men with benign asbestos-related lung or pleural diseases. METHODS: Between 2008 and 2018, 2439 male participants of a German surveillance program for asbestos workers were included in the cohort. All participants had a recognized occupational asbestos-related disease of the pleura or lung. We estimated the mesothelioma and lung cancer risks by calculating standardized incidence ratios (SIR) with corresponding 95% confidence intervals (95% CI). RESULTS: We observed 64 incident lung cancer and 40 mesothelioma cases in the cohort. An SIR of 17.60 (95% CI: 12.57-23.96) was estimated for mesothelioma and 1.27 (95% CI: 0.98-1.62) for lung cancer. The presence of pleural plaques was associated with a strongly increased risk (SIR: 13.14; 95% CI: 8.51-19.40) for mesothelioma, but not for lung cancer (SIR: 1.05; 95% CI: 0.76-1.41). The highest lung-cancer risk (SIR: 2.56; 95% CI 1.10-5.04) was revealed for cohort members with less than 40 years since first asbestos exposure. Lung cancer risks by duration of asbestos exposure did not show a consistent time trend, but for time since last exposure a trend for mesothelioma was seen. CONCLUSIONS: Compared to the general population, we demonstrated an association between benign asbestos-related lung or pleural disease and mesothelioma risk in workers with a history of occupational asbestos exposure. Because lung-cancer risk is dominated by smoking habits, a possible effect of asbestos exposure may have been masked. Efforts should be made to ban production and use of asbestos worldwide and to establish safe handling rules of legacy asbestos.

Radiographic diagnosis of Pneumoconioses by AIR Pneumo-trained physicians: Comparison with low-dose thin-slice computed tomography.

OBJECTIVES: The Asian Intensive Reader of Pneumoconiosis (AIR Pneumo) is a training program designed to improve diagnostic skills for chest radiographies (CXRs) in accordance with the ILO/ICRP 2000. The purpose was to determine the prevalence of occupational environmental pulmonary disease findings in construction workers on thin-slice computed tomography (thin-slice CT), and to compare the diagnostic performance with CXR evaluated by AIR Pneumo-trained physicians. METHODS: Ninety-seven male construction workers underwent low-dose thin-slice CT and CXR on the same day. NIOSH B reader and a board-certified radiologist each interpreted the thin-slice CTs independently. The concordant findings on thin-slice CT were established as the reference standard and were statistically compared with CXRs. Four physicians interpreted CXRs independently according to the ILO/ICRP 2000. RESULTS: Of the 97 cases, nine showed irregular or linear opacities, and 44 had pleural plaques on thin-slice CT. Five, four, three, and two of nine cases with irregular opacity were detected by the four readers on CXRs, respectively. Sixteen, 14, 9, and 5 of the 44 cases with pleural plaques were detected by the four readers, respectively. Specificities for irregular opacities ranged from 94% to 100%, and those for pleural plaques were from 86% to 96%. CONCLUSIONS: Thin-slice CT-detected irregular opacity was found in 9.3%, whereas pleural plaque was found in 45.4% among the construction workers. Chest radiography showed acceptable performance in classifying pneumoconiotic opacities according to ILO/ICRP 2000 by the AIR Pneumo and/or NIOSH-certified physicians.

The Effects of Asbestos Fibers on Human T Cells.

Asbestos exposure causes malignant tumors such as lung cancer and malignant mesothelioma. The effects of asbestos fibers on immunocompetent cells, however, have not been well studied. Asbestos physically comprises a fibrous substance, which differs from silica particles which are a particulate substance, although chemically it is a mineral silicate. Since silicosis patients previously exposed to silica particles often suffer from lung and autoimmune diseases, it is clear that silica exposure impairs immune tolerance. Similarly, asbestos may alter the immune system in asbestos-exposed individuals. Given that malignant tumors can result following exposure to asbestos, the attenuation of anti-tumor immunity in cases of asbestos exposure is an important area of investigation. We observed the effect of asbestos fibers on T lymphocytes, such as CD8+ cytotoxic T lymphocytes (CTLs), CD4+ helper T (Th), and regulatory T (Treg) cells, and showed that anti-tumor immunity was attenuated, as demonstrated in a system that stimulates fresh cells isolated from peripheral blood in vitro and a system that is continuously exposed to a cell line. In this manuscript, we introduce the experiments and results of studies on CTLs, as well as Th and Treg cells, and discuss how future changes in immunocompetent cells induced by asbestos fibers can be clinically linked.

Pleural Plaques and the Risk of Lung Cancer in Asbestos-exposed Subjects.

Rationale: Asbestos exposure is associated with a dose-dependent risk of lung cancer. The association between lung cancer and the presence of pleural plaques remains controversial.Objectives: To define the relationship between pleural plaques and lung cancer risk.Methods: Subjects were from two cohorts: 1) crocidolite mine and mill workers and Wittenoom Township residents and 2) a mixed-asbestos-fiber, mixed-occupation group. All subjects underwent annual review since 1990, chest X-ray or low-dose computed tomography scan, and outcome linkage to national cancer and mortality registry data. Cox regression, with adjustment for age (as the underlying matching time variable), was used to estimate hazard ratios (HRs) for lung cancer incidence by sex, tobacco smoking, asbestos exposure, presence of asbestosis, and pleural plaques.Measurements and Main Results: For all 4,240 subjects, mean age at follow up was 65.4 years, 3,486 (82.0%) were male, 1,315 (31.0%) had pleural plaques, and 1,353 (32.0%) had radiographic asbestosis. Overall, 3,042 (71.7%) were ever-smokers with mean tobacco exposure of 33 pack-years. In total, 200 lung cancers were recorded. Risk of lung cancer increased with cumulative exposure to cigarettes, asbestos, and presence of asbestosis. Pleural plaques did not confer any additional lung cancer risk in either cohort (cohort 1: HR, 1.03; 95% confidence interval, 0.64-1.67; P = 0.89; cohort 2: HR, 0.75; 95% confidence interval, 0.45-1.25; P = 0.28).Conclusions: The presence of pleural plaques on radiologic imaging does not confer additional increase in the risk of lung cancer. This result is consistent across two cohorts with differing asbestos fiber exposures and intensity.

[Asbestos and its effects on health of Icelanders - review].

Asbestos are crystallized silicate minerals that form fibers with different structures and characteristics. Asbestos fibers are very durable and can tolerate very high temperatures. Therefore it was common to use asbestos as a fire retardants, heat insulation and where high temperature is used. Asbestos has been banned in Iceland from 1983 but can still be found in large amounts in buildings, ships and hot water pipes. Large amounts of asbestos were imported in the years before the ban but diminished soon to almost nothing today. Needle or filamentous shaped dust is released when working with asbestos. It is this dust that is dangerous for health. The latent time from exposure to disease can be up to forty years. Asbestos reaches the lungs via inhalation and can cause asbestosis that is a form of lung fibrosis with slow progression. Asbestos can also cause benign pleural effusions, pleural plaques and diffuse pleural thickening. Asbestos is a carcinogen. Lung cancer is most common but asbestos is also a risk factor for cancers of other organs. Mesothelioma is most common in the pleura but can be seen in other membranes. The incidence of these tumors is high in Iceland and is still increasing among males. Of all the European countries mortality is highest in Iceland. It is important for physicians to include asbestos exposure in the differential diagnosis of lung diseases and when lung cancer is diagnosed.

Comparison of serum biochemical markers in patients with mesothelioma and pleural plaques versus healthy individuals exposed to environmental asbestos.

BACKGROUND: In this study, we aimed to compare serum biochemical markers in patients with malignant pleural mesothelioma and pleural plaques versus healthy individuals exposed to environmental asbestos. METHODS: Between September 01, 2010 and March 31, 2011, a total of 540 participants (354 males, 186 females; mean age 61.4 years; range, 35 to 89 years) were included in the study. The participants were divided into four groups as follows: (1) patients with pleural plaques (n=277); (2) healthy individuals with normal chest X-rays who were exposed to environmental asbestos (n=121); (3) healthy individuals with normal chest X-rays who were not exposed to environmental asbestos (n=118); and (4) patients with malignant pleural mesothelioma (n=24). Serum levels of carcinoembryonic antigen, cancer antigen 125, 15-3, 19-9, free T3, free T4, thyroidstimulating hormone, vitamin B12, folate, and ferritin were measured. RESULTS: Serum cancer antigen 125, 15-3, folic acid, vitamin B12, and ferritin levels were higher with lower free T3 levels in Group 4 than the other groups. The areas under the curve for cancer antigen 125 and 15-3 were 0.78 and 0.67, respectively in the differential diagnosis of mesothelioma from other pathologies (p<0.001 for both). Optimal limits of these biomarkers were 13.63 and 18.43 ng/mL, respectively with 83% and 75% sensitivity and 69% and 48% specificity, respectively. CONCLUSION: The combination or individual use of serum cancer antigen 125, 15-3, folic acid, vitamin B12, and ferritin levels may be helpful for early diagnosis and treatment of malignant pleural mesothelioma.

Pleural abnormalities in the Framingham Heart Study: prevalence and CT image features.

BACKGROUND: The prevalence of pleural abnormalities in the general population is an epidemiologically important index of asbestos exposure, which has not been investigated since a radiography-based study in 1980. METHODS: We examined 2633 chest CT scans (mean 59.2 years, 50% female) from the Framingham Heart Study (FHS) for the presence and image characteristics of pleural plaques and diffuse pleural thickening. Demographics and pulmonary function were stratified by the presence of pleural abnormalities in association with interstitial lung abnormalities. RESULTS: Pleural abnormalities were present in 1.5% (95% CI 1.1% to 2.1%). Pleural lesions were most commonly bilateral (90.0%), multiple (77.5%), calcified (97.5%) and commonly involved posterior (lower: 92.5%, middle: 87.5%), anterior (upper: 77.5%, middle: 77.5%) and diaphragmatic areas (72.5%). Participants with pleural abnormalities were significantly older (75.7 years, p <0.0001), male (92.5%, p <0.0001), former or current smokers (80.0%, p <0.001) with higher pack-years (33.3, p <0.0001). No significant reduction was noted in pulmonary function measures (p=0.07-0.94) when adjusted for the associated covariates, likely due to small number of cases with pleural abnormalities. Information about prior history of asbestos exposure and occupation was not available. CONCLUSIONS: Pleural plaques and diffuse pleural thickening are present on CT in 1.5% of the FHS cohort. The current prevalence of the pleural abnormalities is smaller than that reported in the previous population-based study using chest radiography, likely representing lower asbestos exposure in recent decades. The posterior portion of the pleura is most frequently involved but the anterior portion is also commonly involved.

Environmental asbestos disease: pleural plaque volume measurement with Chest Tomography is there a correlation between pulmonary function?

Objectives: Chest X-ray is correlated with pulmonary function of asbestos related disease. These correlations limited by low specific and sensitive. Computed tomography (CT) more sensitive. There was no adopted for the measurement of CT. Our aim in this study was to determine correlation between pleural plaque (PP) volume and lung function for use improving classification with CT. Methods: The study included 75 patients with environmental asbestos exposure. PP areas measured in patients were divided by the patient lung area to determine PP ratio with CT. Diffusing capacity and six minute walking distance (6MWD) measured and evaluated quality of life. Results:PP identified in 66 (88%) of the patients with CT. PP most frequently noted in the front right quadrant and had an average plaque volume of 7729,17 mm3. Plaque ratio taken as the percentage of the ratio to the lung volume, mean plaque percentage was 0,37±0,45% (0,003-2,3). In 12(18,1%) of the patients, asbestosis not seen with chest X-ray was detected with CT. Conclusions: PP volume and ratios were not statistically significantly correlated with respiratory functions, exercise capacity, cumulative amount of exposure. Patient of asbestos disease total lung capacity was lower, 6MWD distance was shorter and quality of life was poorer. (Sarcoidosis Vasc Diffuse Lung Dis 2017; 34: 336-342).

Asbestos exposure increases the incidence of histologically confirmed usual interstitial pneumonia.

AIMS: We hypothesized that asbestos exposure increases the incidence of macroscopically visible and histologically confirmed usual interstitial pneumonia (histological UIP). METHODS AND RESULTS: We retrospectively examined 1718 cases (1202 males; mean age 66.7 years) who underwent lobectomy for resection of pleuropulmonary tumours. Objective markers for asbestos exposure included: the presence of malignant pleural mesothelioma, the presence of pleural plaques (PPs) and asbestos bodies in the histological specimen. Risk factors for histological UIP were examined. Two separate groups were studied: 183 with asbestos exposure, and 239 with histological UIP. The 183 cases with asbestos exposure had higher rates of positive occupational history and histological UIP (31%) than the remaining 1535. Among the asbestos-exposed group, small numbers of asbestos bodies were found in histological specimens of 21 cases of histological UIP. PPs and asbestos bodies were more frequent in the 239 patients with histological UIP than in the remaining 1479 UIP-negative patients. Multivariate analysis showed that asbestos exposure, especially positivity for asbestos bodies, that does not meet the current criteria for asbestosis increases the risk of histological UIP (P < 0.0001). CONCLUSIONS: Asbestos exposure causes asbestosis and increases the incidence of histological UIP.

A systematic review of the association between pleural plaques and changes in lung function.

OBJECTIVES: To conduct a systematic review of changes in lung function in relation to presence of pleural plaques in asbestos-exposed populations. METHODS: Database searches of PubMed and Web of Science were supplemented by review of papers' reference lists and journals' tables of contents. Methodological features (eg, consideration of potential confounding by smoking) of identified articles were reviewed by ≥ two reviewers. Meta-analyses of 20 studies estimated a summary effect of the decrements in per cent predicted (%pred) forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) associated with presence of pleural plaques. RESULTS: Among asbestos-exposed workers, the presence of pleural plaques was associated with statistically significant decrements in FVC (4.09%pred, 95% CI 2.31 to 5.86) and FEV1 (1.99%pred, 95% CI 0.22 to 3.77). Effects of similar magnitude were seen when stratifying by imaging type (X-ray or high-resolution CT) and when excluding studies with potential methodological limitations. Undetected asbestosis was considered as an unlikely explanation of the observed decrements. Several studies provided evidence of an association between size of pleural plaques and degree of pulmonary decrease, and presence of pleural plaques and increased rate or degree of pulmonary impairment. CONCLUSIONS: The presence of pleural plaques is associated with a small, but statistically significant mean difference in FVC and FEV1 in comparison to asbestos-exposed individuals without plaques or other abnormalities. From a public health perspective, small group mean decrements in lung function coupled with an increased rate of decline in lung function of the exposed population may be consequential.