Asbestos fiber type in malignant mesothelioma: an analytical scanning electron microscopic study of 94 cases.

Although the association between asbestos exposure and malignant mesothelioma is indisputable, controversy continues regarding the relative contribution of the various types of asbestos fibers to the development of mesothelioma. We examined the types of asbestos fibers recovered from lung parenchyma in more than 90 cases of malignant mesothelioma from the United States, using an analytical scanning electron microscope. Almost half of the patients were former asbestos insulators or shipyard workers. The fibers were recovered from lung tissues obtained at autopsy or surgical resection by means of a sodium hypochlorite digestion procedure. Amosite asbestos was identified in 81% of the cases and accounted for 58% of all fibers 5 microns or greater in length. Tremolite/actinolite/anthophyllite were identified in 55% of the cases and accounted for 10% of all fiber types. Chrysotile was identified in 21% of the cases and accounted for 3% of fibers exceeding 5 microns in length. Crocidolite was found in 16% of the cases and accounted for 3% of fibers exceeding 5 microns in length. Nonasbestos mineral fibers (commonly found in the lungs of the general population) were observed in 71% of the cases and accounted for 25% of all fibers 5 microns or greater in length. The findings in this study are at odds with the assertion that crocidolite asbestos is responsible for most mesotheliomas in the United States.

Polysplenia with pulmonary arteriovenous malformations.

A patient with polysplenia syndrome, dextrocardia, left atrial isomerism, normal great vessel relationships, and no intracardiac shunts developed progressive cyanosis and clubbing. Pulmonary arteriovenous malformations (PAVMs) were diagnosed by angiography and confirmed by lung biopsy. Superior mesenteric arteriogram revealed hypoplasia of the intrahepatic portal vein branches and a portosystemic shunt. The possible etiologies of PAVMs are discussed.

The emphysemas: radiologic-pathologic correlations.

There are several forms of emphysema that should be considered as distinct disease entities. No university accepted classification system of these forms exists, but correlations of autopsy findings in 1,823 cases over a 12-year period confirm that the radiographic and pathologic features of the emphysemas are readily understood when centrilobular, panlobular, paracicatricial, and localized types of the disease are recognized. Centrilobular emphysema associated with cigarette smoking is the most common form. Panlobular emphysema is associated with alpha 1-protease inhibitor deficiency and pathologically produces uniform enlargement of all air spaces, with a mild basilar predominance. Paracicatricial emphysema is seen adjacent to areas of parenchymal scarring. Localized emphysema represents focal enlargement or destruction of air spaces with otherwise normal lung. A clear understanding of the computed tomographic appearance of all forms of emphysema is essential for the correct diagnosis of parenchymal lung abnormalities.

Neutrophil elastase activity and superoxide production are diminished in neutrophils of alcoholics.

Several lines of evidence indicate that neutrophil elastase and oxidants secreted by phagocytic inflammatory cells play key roles in the development of centrilobular emphysema. A recent report suggests that ethanol consumption may have a protective role against this disease in smokers. The aim of this study was to examine the effect of ethanol consumption on neutrophil elastase activity and superoxide production of peripheral blood neutrophils. These activities were measured in neutrophils from 52 male intoxicated patients and compared to activities in neutrophils from 20 male volunteers. Neutrophils from intoxicated patients contained 31% less elastase activity than that found in controls, 0.99 +/- 0.27 versus 1.44 +/- 0.23 micrograms/10(6) neutrophils (p less than 0.0001) and produced 25 to 27% less superoxide than controls in response to phorbol 12-myristate-13-acetate, 0.90 +/- 0.17 versus 1.2 +/- 0.21 nmol/min/10(6) PMN (p less than 0.0001) or N-formylmethionylleucylphenylalanine, 0.64 +/- 0.19 versus 0.88 +/- 0.24 (p less than 0.001). In follow-up studies of 10 patients admitted for acute alcoholism, elastase activity and superoxide production remained low for 2 to 4 days. After 6 to 10 days, elastase activity and superoxide production were significantly greater than they were at Day 0 and approached normal levels. Neutrophils isolated from blood samples of healthy abstaining donors, which had been exposed to ethanol or to plasma from inebriated patients for 16 to 20 h, showed no loss of elastase activity or superoxide production.(ABSTRACT TRUNCATED AT 250 WORDS)

Lower incidence of death from chronic renal disease in patients with nonlethal emphysema: a statistical study.

Pulmonary emphysema is an extraordinarily prevalent disease, especially among men, and is found in about 40% of all autopsies at this Veterans Medical Center. However, in the great majority of cases, it is an incidental finding, and the individual has died of another lesion, either pulmonary or in another organ system. These facts have permitted the authors to examine the interrelationships between presence or absence of emphysema and the cause of death in a consecutive series of 1033 autopsies. Results show that chronic renal disease is much less common as a cause of death in persons with, than in those without, emphysema. Since emphysema is closely associated with smoking, the data also show a reduction in risk of death from renal disease in smokers. These trends persist, even when individuals who have died from smoking-related diseases are eliminated from the population. Further analyses suggest that it is the presence of emphysema which is mainly responsible for this effect. A likely mechanism for it is proposed.

Radiographic appearance of the chest in emphysema.

The essential point of this analysis is that, although arterial deficiency was shown to be virtually useless as a diagnostic criterion for emphysema, it does not follow that use of other validated radiographic criteria for diagnosing and excluding emphysema, using conventional films, should be abandoned. Interested readers can find further detailed information in reference 1.

Role of conventional chest radiography in diagnosis and exclusion of emphysema.

Although recognizing that the subject is controversial, most authors of textbooks about diagnostic radiology conclude that chest radiography is of little value for either confirmation or exclusion of the diagnosis of emphysema. Yet several reports in the literature show a high degree of accuracy in the interpretation of films for presence of this disease. Some of the controversy results from continuing confusion over the current definition of emphysema in terms of lung structure rather than symptoms or physiologic evidence relating to impaired ventilation. Many autopsy studies have shown that emphysema is often present at postmortem examination and can involve as much as 30 percent of the lung tissue, even in subjects with no respiratory symptoms or impairment during life. Since radiographs deal with structure rather than function, interpreters of chest films should have the intention to recognize the presence of structural emphysema. The correct recognition of emphysema is useful even in a patient without symptoms, and the ability to exclude this diagnosis in symptomatic patients is of equal, if not greater value. The degree of success reported in various studies depends upon the criteria used and the strictness applied by the authors in matching their interpretations to the presence or absence of structural emphysema. This review of existing literature deals solely with papers in which radiographic observations have been related to morphologic evidence of emphysema in inflation-fixed autopsy lung specimens. It identifies reasons for discrepancies among reports and emphasizes the very high predictive value of validated radiographic criteria. Applications of radiographic interpretation both for diagnosis and for exclusion of emphysema in clinical situations are described.

Centrilobular emphysema: CT-pathologic correlation.

Over a 5-year period, 25 patients who had undergone chest computed tomography (CT) died and were autopsied. Their lungs were fixed in the inflated state and were assessed for the presence and severity of centrilobular emphysema (CLE). Three radiologists independently evaluated the CT scans for nonperipheral low-attenuation areas, peripheral low-attenuation areas, pulmonary vascular pruning, pulmonary vascular distortion, and pulmonary density gradient. The CT criterion that best correlated with the presence and severity of CLE was the nonperipheral low-attenuation area. With this CT criterion, lung destruction was correctly identified in 13 of 15 cases. The absence of this criterion resulted in correct identification of eight of ten normal lungs. These preliminary data suggest that CLE can be reliably identified and quantified with current CT scanners.

Asbestos content of lung tissue in asbestos associated diseases: a study of 110 cases.

Diseases associated with asbestos exposure include asbestosis, malignant mesothelioma, carcinoma of the lung, and parietal pleural plaques. In this study the asbestos content of lung tissue was examined in groups of cases representing each of these diseases and in several cases with non-occupational idiopathic pulmonary fibrosis. Asbestos bodies (AB), which are the hallmark of asbestos exposure, were present in the lungs of virtually everyone in the general population and present at increased levels in individuals with asbestos associated diseases. The highest numbers of AB occurred in individuals with asbestosis, all of whom had levels greater than or equal to 2000 ABs/g wet lung tissue. Every case with a content of 100,000 ABs/g or higher had asbestosis. Intermediate levels occurred in individuals with malignant mesothelioma and the lowest levels in patients with parietal pleural plaques. There was no overlap between the asbestos content of lung tissue from patients with asbestosis and those with idiopathic pulmonary fibrosis. Lung cancer was present in half the patients with asbestosis, and the distribution of histological patterns did not differ from that in patients with lung cancer without asbestosis. The asbestos body content in patients with lung cancer was highly variable. Control cases had values within our previously established normal range (0-20 ABs/g). There was a significant correlation (p less than 0.001) between AB counted by light microscope and AB and uncoated fibres counted by scanning electron microscopy. The previous observation that the vast majority of asbestos bodies isolated from human tissues have an amphibole core was confirmed.