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Asbestosis, defined as diffuse pulmonary fibrosis caused by inhalation of asbestos fibers, occurs after heavy exposures to asbestos dust over several decades. Because workplace exposures have been significantly curtailed since the banning of asbestos in insulation products, we were interested in examining the clinicopathological characteristics of cases diagnosed in the 21st century. The consultation files of one of the authors (VLR) were reviewed for cases of asbestosis diagnosed since 1/1/2001. 102 cases were identified, with a median age of 75 years (range: 45–89). There were 100 men and 2 women. The women were from Turkey and Brazil (none from the United States). Malignancies were present in 78 cases, including 38 lung cancers, 29 pleural mesotheliomas, and 8 peritoneal mesotheliomas. The grade of asbestosis was available in 88 cases (median severity of 2; scale: 1–4). Pleural plaque was present in 94% of cases. The most common exposure categories were insulators (39), shipyard workers (16), asbestos manufacturing (9), boiler workers (8) and pipefitter/welders (6). The median duration of exposure was 33 years (range: 2–49 years). Lung fiber burden analysis was performed in 34 cases, with amosite being the predominant fiber type. Results were compared with similar information for 475 cases diagnosed prior to 1/1/2001. [ABSTRACT FROM AUTHOR]

Malignant mesothelioma is strongly associated with prior asbestos exposure. Recently there has been interest in the role of talc exposure in the pathogenesis of mesothelioma. We have analyzed lung tissue samples from a large series of malignant mesothelioma patients. Asbestos bodies were counted by light microscopy and mineral fiber concentrations for fibers 5 µm or greater in length were determined by scanning electron microscopy equipped with an energy dispersive spectrometer. The values were compared with 20 previously published controls. Among 609 patients with mesothelioma, talc fibers were detected in 375 (62%) and exceeded our control values in 65 (11%). Elevated talc levels were found in 48/524 men (9.2%) and 17/85 women (20%). Parietal pleural plaques were identified in 30/51 informative cases (59%) and asbestosis in 5/62 informative cases (8%). Commercial amphiboles (amosite and/or crocidolite) were elevated in 52/65 (80%) and noncommercial amphiboles (tremolite, actinolite or anthophyllite) in 41/65 (63%). Both were elevated in 34/65 (52%). Asbestos body counts by light microscopy were elevated in 53/64 informative cases (83%). A history of working in industries associated with asbestos exposure and increased mesothelioma risk was identified in 36/48 cases in men, and a history of exposure as household contacts of an occupationally exposed individual was identified in 12/17 cases in women. We conclude that among patients with mesothelioma, the vast majority have talc levels indistinguishable from background. Of the remaining 11% with elevated talc levels, the vast majority (80%) have elevated levels of commercial amphibole fibers. [ABSTRACT FROM AUTHOR]

A variety of fibrotic lung diseases are caused by the inhalation of organic dusts. Many of these disorders have distinctive histopathology and can be readily diagnosed by routine histopathologic examination. However, in some instances, there is overlap in morphology between diseases caused by dust inhalation (mineral pneumoconiosis) and other lung diseases. In such cases, analytical scanning electron microscopy (SEM) can provide valuable information to assist the pathologist in making the correct diagnosis. We report herein our findings in 96 cases in which in situ particle analysis (ISPA) was performed with the SEM. This included 56 cases of pneumoconiosis as well as 40 cases of other types of interstitial lung disease. The most common diagnosis for which ISPA was performed in individuals with pneumoconiosis was mixed dust pneumoconiosis (14 cases). The most common diagnoses for which ISPA was performed in individuals with other diseases were sarcoidosis (13 cases) and hypersensitivity pneumonitis (10 cases). In addition to a detailed description of our methodology, we also report other circumstances in which ISPA assists in the diagnosis of pulmonary disease. [ABSTRACT FROM AUTHOR]

Lung tissue from 42 peritoneal mesothelioma cases was analyzed by light microscopy and scanning electron microscopy/energy dispersive spectrometry. There were 34 men and 8 women with a mean age of 61 ± 10 years. Also, 17% of cases had histologically confirmed asbestosis, and 26% had only parietal pleural plaques. The asbestos body count exceeded our normal range in 22 of 42 cases (52%). Cases with asbestos-related pulmonary disease had higher fiber burdens than those without. The vast majority of fibers were commercial amphiboles (amosite with lesser amounts of crocidolite). These findings concur with previously published epidemiological observations. [ABSTRACT FROM AUTHOR]

Epidemiological studies indicate that 80–90% of mesotheliomas are asbestos related. This suggests that 10–20% are not. Lung fiber burden analysis provides objective information about past exposures to asbestos. We have performed lung fiber burden analysis on a large cohort of mesothelioma cases and compared the findings with a reference population. Herein we report our findings along with demographic and exposure data. [ABSTRACT FROM AUTHOR]

Ultrastructural examination remains a crucial diagnostic tool for analysis of renal biopsies, along with light and immunofluorescence microscopy. Several advantages of electron microscopy are the ability to detect most forms of glomerular disease/dysfunction; the ability to examine small, suboptimal, or unusual specimens; and superior resolution that allows the investigator to hunt without preconceived ideas of what he/she is looking for or will find. A few shortcomings must be noted for completeness, including inability to detect disorders without specific ultrastructural signature, biochemical heterogeneity of deposits with similar or identical ultrastructural appearances, and occasional false-negative results in diseases with focal manifestations. [ABSTRACT FROM AUTHOR]

Tran and colleagues have taken issue with our use of control or reference ranges in our article regarding 'Talc and Mesothelioma: Mineral Fiber Analysis of 65 Cases with Clinicopathological Correlation'.[1] We did not use a "single" control to establish our background range for talc in the reference population, but instead 20 control cases that had been used as a reference population in prior studies.[2] As clearly indicated in Table 1, talc was detected in 11 of our 20 control cases. Careful reading of our paper as well as most of our other fiber analysis publications indicates that tremolite, actinolite and anthophyllite are combined in all cases in that study, and not just in case 24. [Extracted from the article]