[Medical insurance aspects of peritoneal tumors with particular attention to peritoneal mesotheliomas]. / Versicherungsmedizinische Aspekte bei peritonealen Mesotheliomen und sonstigen peritonealen Tumoren.

Malignant peritoneal mesotheliomas arise mainly in male patients and the median age of initial diagnosis is about 56 years. Epitheloid subtype predominates in peritoneal mesotheliomas. Asbestos exposure is the best-known and most common risk factor associated with the development of both pleural and peritoneal mesotheliomas and, therefore, about 90% of cases can be assessed as asbestos-associated. Patients with peritoneal mesotheliomas have distinctly higher asbestos burden of the lungs than patients with pleural mesotheliomas. The mean latency period between exposure and diagnosis of peritoneal mesothelioma ranges from 35 to 40 years and is comparable to that of pleural mesothelioma. Mesothelioma of the tunica vaginalis testis also belongs to the group of peritoneal mesotheliomas. No significant evidence exists for the classification of well-differentiated papillary mesothelioma, solitary fibrous tumor, adenomatoid tumor, primary peritoneal serous borderline tumor, and benign multicystic mesothelioma as asbestos-associated tumors. Except malignant mesotheliomas, the induction of other abdominal tumors is independent of an exposure to asbestos dust.

Interobserver variations in diagnosing asbestosis according to the ILO classification.

Inhalation of asbestos fibres leads to asbestosis of the pleura and the lung, with possible progression to lung cancer and malignant pleural or peritoneal mesothelioma. Asbestosis remains difficult to diagnose, especially in its early stages. The most important role in its diagnosis is that of chest radiographs. The aim of this cross-sectional study was to address interobserver variations in interpreting chest radiographs in asbestos workers, which remain to be an issue, despite improvements in the International Labour Office (ILO) classification system. In our ten-year study, we investigated 318 workers occupationally exposed to asbestos, and in 210 workers with diagnosed asbestos-related changes we compared interpretations of chest radiographs according to ILO by two independent radiologists. The apparent degree of interobserver variation in classifying lung fibrosis was 26.66% for the diameter of changes and 42.2% for the profusion of the changes. In cases with diffuse pleural thickening, the interobserver variation using ILO procedures was 34.93%. This investigation raises the issue of standardisation and objectivity of interpretation of asbestosis according to the ILO classification system. This study has revealed a significant disagreement in the estimated degree of pleural and parenchymal asbestos pulmonary disease. This is why we believe high-resolution computed tomography (HRCT) should also be used as a part of international classification.

[Macroscopic subtypes of asbestosis in relation to the amount of asbestos in 63 Japanese autopsy cases].

Atelectatic induration (AI) and honeycombing (HNCB) are two distinct macroscopic features of asbestosis. The current study was undertaken to clarify whether or not there might be a relation between the macroscopic type of asbestosis and burden of asbestos fibers in the lung. The material (N = 63) derived from 58 autopsies and 5 surgically removed lungs with lung cancers, which comprised 22 cases of AI (mean age: 67 years: 20 males and 2 females) and 41 cases of HNCB (mean age: 66 years: 38 men and 3 women) types of asbestosis, respectively. The quantification of asbestos bodies (AB) and fibers (AF) was carried out using Kohyama's method. The AI type showed 260,000 +/- 460,000 AB per 1g of wet lung and 920,000 +/- 1,360,000 AF per 1g of dry lung, whereas HNCB showed 44,000 +/- 93,000 AB and 200,000 +/- 490,000 AF, respectively. These differences were statistically significant between the types of asbestosis (p < 0.01). Diffuse pleural thickening and upper lobe involvement were more advanced in the AI type and the differences were statistically significant between subtypes (p < 0.05). In conclusion, asbestos load is considered to be a factor related to the macroscopic subtype of asbestosis.

Radiographic readings for asbestosis: misuse of science--validation of the ILO classification.

BACKGROUND: Radiographic readings for pneumoconiosis (both asbestosis and silicosis), even those using the International Labour Office (ILO) Classification, have received widespread negative coverage in the media and strong judicial rebuke. METHODS: The medical literature over the past 90 years was reviewed for the relationships between radiographic severity (standardized as the ILO profusion score) and indices of exposure to silica or asbestos, tissue burden of silica particles or asbestos fibers, histologic fibrosis, various measurements of pulmonary function and mortality. RESULTS: Evidence from many different disciplines has demonstrated that the ILO profusion score correlates with occupational exposure, dust burden in the lung, histologic fibrosis and, more recently, with physiologic impairment and mortality. CONCLUSIONS: The ILO Classification has therefore been validated as a scientific tool. Its fraudulent misuse by "hired-gun" physicians, attorneys and elements of the compensation system to falsify claims of asbestosis and/or silicosis (often in the same claimant) must be condemned.

Asbestos-related pleural diseases: dimensional criteria are not appropriate to differentiate diffuse pleural thickening from pleural plaques.

BACKGROUND: In the literature, the criteria used to define pleural plaques (PP) and diffuse pleural thickening (DPT) are very heterogeneous and often imprecise. A multicenter restropective study was conducted to assess the relevance of two radiographic definitions of DPT. METHODS: The study population consisted of 287 subjects with asbestos-related pleural thickening. Two definitions were used to characterize DPT on postero-anterior chest radiographs: definition 1: pleural thickening associated with obliteration of the costophrenic angle; definition 2: pleural thickening at least 5 mm wide, extending for more than one quarter of the chest wall. Prevalence of respiratory symptoms and pulmonary function tests were compared in the DPT and PP groups resulting from the two definitions of DPT. RESULTS: According to definition 1, 34 patients (11.8%) were classified in the DPT group. Prevalence of chronic sputum, dyspnea, and chest pain was significantly higher in this group than in the PP group. FEV(1), FVC, and TLC were significantly lower. The differences persisted after adjustment for confounding factors. According to definition 2,102 patients (36.6%) were classified in the DPT group. DPT and PP groups did not differ in terms of prevalence of respiratory symptoms, or pulmonary function tests. Agreement between readers was significantly better when using definition 1. CONCLUSIONS: Obliteration of costophrenic angle is a much more reliable sign than dimensional criteria to characterize DPT.

High-resolution computed tomography classification of lung fibrosis for patients with asbestos-related disease.

OBJECTIVES: This study tested a new high-resolution computed tomography (HRCT) scoring method for asbestos-induced parenchymal changes in the lung. METHODS: HRCT scans of 602 asbestos-exposed workers and 49 referents were reviewed by 3 radiologists. Structured forms were filled out for a semiquantitative HRCT fibrosis score based on several specified parenchymal abnormalities scored separately. Observer agreement was studied with the use of the quadratic-weighted kappa (kappaqw). The HRCT fibrosis score (from 0 to V with definitions and index images given retrospectively) was compared with the radiographic classification of the International Labour Office (ILO) for the same patients. Receiver-operating characteristic (ROC) curves were computed to compare the tests for diagnosing asbestosis. RESULTS: Good inter- and intraobserver agreements were achieved (kappaqw = 0.64 and 0.72, respectively) as regards the HRCT fibrosis score. All the specified computed tomography findings explained 86% of the variance in the HRCT fibrosis score. Age and occupational group were significant predictors of fibrosis. The area under the ROC curve was significantly greater for the HRCT fibrosis score (0.89) than for the ILO radiographic classification (0.76). The sensitivity (70%) and specificity (91%) of the HRCT fibrosis score (classes I/II-V representing asbestosis) were better than those of the classification published by the International Labour Office (51% and 89%, respectively, score > or = 1/0 representing asbestosis). CONCLUSIONS: The examined HRCT scoring method proved to be a simple, reliable, and reproducible method for classifying lung fibrosis and diagnosing asbestosis also in large populations with occupational disease, and it would be possible to use it as a part of an international classification.

Computer-assisted classification system for chest X-ray and computed tomography findings in occupational lung disease.

The ILO classification of pneumoconiotic changes in the lungs and pleura has become a standardized and widely accepted method of documentation in occupational medicine. Recently a classification system for computed tomography/high-resolution computed tomography (CT/HRCT) findings in the lung has been proposed as well. For both classification systems, computed-assisted programs have been developed that allow the storage and archiving of the results as well as further statistical processing. The programs are compatible with usual hardware configurations, have a comprehensible and transparent structure, and are easy to learn and adaptable to individual needs. The use of the computer-assisted classification systems is presented in the example of an insulator exposed to asbestos. The system of data documentation and processing has proved to be very practicable in the more than 2000 patients studied thus far.

Evaluation and classification of high-resolution computed tomographic findings in patients with pneumoconiosis.

The standard ILO classification for pneumoconiotic changes using conventional X-ray films has become well established. In recent years computed tomography has played an increasing role in occupational medicine and above all in the assessment of pneumoconiosis. Therefore a standardised method of classification for CT also seems necessary. A system of classification developed by occupational hygienists and radiologists allows a detailed description of parenchymal and pleural changes and the use of 28 additional symbols. Furthermore, special diagnoses relevant to occupational medicine and additional comments can be made. The classification system was tested in practice in the research project "Early diagnosis of asbestos-related diseases" (Frühdiagnostik asbestverursachter Erkrankungen). It was shown to be both practicable and easily reproducible, intra-individually and interindividually.

Asbestos-related radiographic changes by ILO classification of 10 x 10 cm chest X-rays in a screening of the general population.

A sample of 1388 10 x 10 cm chest X-rays from a previous population screening of males aged 40+ years were reevaluated by use of the ILO classification. There were 1036 films of subjects from an industrialized town, and 352 from a rural community. The observed rates of parenchymal changes (profusion > or = 1/0) at the reevaluation were 1.3% in the urban community and 3.4% in the rural community. The corresponding figures for pleural changes were 5.0% and 0.6%, respectively. Based on additional questionnaire information on asbestos exposure, it was found that the radiographic changes were probably related to past asbestos exposure for 2.3% of the subjects from the urban community and 0.6% from the rural community. In cases of asbestos-related illnesses the mean time since first exposure to asbestos was 35.9 years, whereas the mean duration of the exposures was 11.4 years. The results seem to indicate that the ILO reassessment of the radiographs was more sensitive in detecting pleural changes than the previous clinical screening of both small and large films.

[The incidence of airway obstruction in asbestosis]. / Zur Häufigkeit einer Atemwegsobstruktion bei der Asbestose.

In a retrospective study we have examined the clinical data, radiographs and lung function of 382 men with an asbestosis, established by occupational exposure and typical findings in the chest x-ray, according to the ILO-classification from 1980. In particular the correlation between airflow limitation, asbestosis of lung and/or pleura and smoking habits was investigated. However the mean values of parameters were only marginally pathological, lifetime non-smokers showed a significant increase of airway obstruction in connection with advanced radiologic alterations. Current smokers with medium or severe radiologic alterations had on average a significant airway obstruction which was more pronounced in cases with pleural lesions than with pulmonary alterations. In conclusion an additive or even multiplying effect of smoking and asbestosis has to be considered.

The left-sided predominance of asbestos-related pleural disease.

In a series of 406 subjects with a diagnosis of asbestos-related pleural disease (ARPD), the left-right symmetry of radiographically diagnosed ARPD was assessed using the International Labour Organization (ILO) system for classifying radiographic abnormalities and three different statistical models for testing the degree of symmetry. The extent of chest disease was found to be greater on the left than on the right for a number of parameters of pleural disease, including the width and extent of localized pleural thickening, the extent of enface pleural thickening, and the extent of diaphragmatic and chest wall calcification. Current cigarette smoking significantly enhanced the observed asymmetry, with the most pronounced effect being in diaphragmatic calcification. Using a composite scale for each subject's pleural disease, the left side had 1.6 times more localized disease than did the right (p < 0.001). Asymmetry in one parameter was associated with asymmetry in another for a number of pairs. The most significant of these associations was between enface pleural thickening and chest wall calcification (Kendall's tau B = 0.42). The pathophysiologic mechanisms that explain these findings remain elusive and need further investigation.

A diagnostic approach to asbestosis, utilizing clinical criteria, high resolution computed tomography, and gallium scanning.

Seventy-five individuals known to have significant exposure to asbestos were evaluated by physical exam, pulmonary function tests (PFT), chest radiographs, high resolution computed tomography (HRCT), gallium-67 scanning, and various laboratory exams. Sixteen subjects met three of the following four criteria and were considered to have clinical asbestosis: 1) bibasilar rales, 2) FVC < 80% of predicted, 3) DLCO < 80% of predicted, and 4) an abnormal chest radiograph. Evaluations which included HRCT and Ga scanning detected pulmonary disease in these asbestos-exposed individuals in many cases where other modalities were unable to demonstrate significant abnormalities. While only 21% of the subjects satisfied commonly accepted criteria for the diagnosis of asbestosis, 75% had evidence of disease by both HRCT and gallium scanning. These data suggest that it may be time to include HRCT and Ga scanning when evaluating asbestos-exposed individuals, especially in cases where evaluations by physical exam, PFTs, and chest radiographs are non-diagnostic.

Chest radiography in dust-exposed miners: promise and problems, potential and imperfections.

Since the early 1900s, it was recognized that many dust-exposed workers developed abnormal radiographs during life. Chest radiography remains the primary means of determining the presence and extent of dust-induced pneumoconiosis, although it is ineffective for detecting airways obstructions from mine dust exposure. This chapter reviews the uses and limitations of chest radiography in the study, surveillance, screening, clinical diagnosis, and disability determinations of occupational lung diseases in dust-exposed workers.

[Pleural fibrosis in asbestosis and ventilatory function: a study of 50 cases]. / Fibrosi pleuriche asbestosiche e funzione ventilatoria: studio di 50 casi.

The importance of non-malignant pleural fibrosis in asbestosis in relation to respiratory function is still open to debate because of the differing results obtained in studies of different population groups. In the present study we selected 50 subjects with occupational exposure to asbestos presenting mono- or bilateral pleural fibrosis at X-ray but without lung impairment. Each subject underwent bronchial lavage and ventilatory function tests. The subjects were divided into 4 groups on the basis of the degree of pleural alterations according to the ILO Classification of Pneumoconioses. The results revealed that the mean values of CV and FEV1 in each group were within physiological limits. Moreover, analysis of the type of lung function showed a normal situation in 64% and restricted function in 28% of the cases. The prevalence of the latter finding was not correlated to the severity of pleural fibrosis in the various groups. Also, comparison between severity of pleural fibrosis and number of asbestos bodies/ml of BAL liquid on the one hand and frequency of alveolitis on the other did not reveal any relationship. Therefore, the onset of pleural fibrosis appears to be independent of the quantity of inhaled asbestos fibres and due to different mechanisms from those leading to lung fibrosis. In practice, a correct interpretation of the presence of pleural fibrosis from a clinical and prognostic viewpoint also requires other investigations such as BAL and a complete respiratory function study.