Desquamative interstitial pneumonia in an aluminum welder

Interstitial pulmonary disease and aluminum trihydrate exposure: A single case report and detailed workplace analysis

Exposure to aluminum compounds is clearly associated with pulmonary function decrements, and several animal models document possible mechanisms of aluminum- compound-induced pulmonary toxicity. Nevertheless, disagreements remain about the precise mechanism by which exposures lead to damage. We present a strong case for attributing a case of interstitial pulmonary disease to occupational exposure to aluminum trihydrate. This report follows a 2014 publication of another case of interstitial pulmonary disease following a similar exposure. Our patient eventually underwent double lung transplantation nearly 5 years postexposure. Detailed pulmonary particulate elemental analysis suggested that aluminum metal, including aluminum trihydrate, was the most likely cause. A detailed assessment of the worker's relevant occupational exposures accompanies this case report.

Pulmonary sarcoid-like granulomatosis induced by aluminum dust: A case report and literature review

Case report

We present a case of a 48-year-old woman with 27 months of exposure to aluminum dust and silica owing to polishing processing. The patient was admitted to our hospital with intermittent cough and expectoration. Chest high-resolution computed tomography showed diffuse ill-defined centrilobular nodules and patchy ground-glass opacities in bilateral lungs. A video-assisted thoracoscopic surgery biopsy demonstrated multiple isolated and confluent granulomas in an otherwise normal parenchyma without malignancy or signs of infection. Elemental analysis was performed on the grinding wheel powder in the workplace using an X-ray fluorescence spectrometric analyzer, showing 72.7% of Al₂O₃ and 22.8% of SiO₂ as raw materials. She was diagnosed with aluminum-associated sarcoid-like granulomatous lung disease, rather than sarcoidosis, according to occupational exposure by a multidisciplinary panel.

Conclusion

Occupational aluminum dust exposure may induce pulmonary sarcoid-like granulomatosis recognized by a multidisciplinary diagnostic panel.

Desquamative interstitial pneumonia: a systematic review of its features and outcomes

Background

Desquamative Interstitial Pneumonia (DIP) is a rare form of idiopathic interstitial pneumonia (IIP). Data on clinical features, aetiology, prognosis and effect of treatment strategies are limited. We aimed to collect all published cases to better characterise DIP.

Methods

A systematic literature search was performed for all original cases of adult patients with histopathologically-confirmed DIP. Individual patient data were extracted and summarised.

Results

We included 68 individual cases and 13 case series reporting on 294 cases. Most common presenting symptoms were dyspnoea and cough. Pulmonary function showed a restrictive pattern (71%) with decreased diffusion capacity. We found a high incidence (81%) of ever smoking in patients with DIP and 22% of patients had other (occupational) exposures. Characteristic features on high-resolution computed tomography (HRCT) scan were bilateral ground-glass opacities with lower lobe predominance (92%). Treatment and duration of treatment widely varied. Initial response to treatment was generally good, but definitely not uniformly so. A significant proportion of patients died (25% of individual cases) or experienced a relapse (18% of individual cases).

Conclusion

DIP remains an uncommon disease, frequently but not always related to smoking or other exposures. Furthermore, DIP behaves as a progressive disease more often than generally thought, possibly associated with different underlying aetiology.

This systematic review is the most comprehensive collection of published cases of DIP to date and yields novel information about aetiology, clinical characteristics, radiology and pathology features, treatment and outcomes.http://bit.ly/394YRPv

Desquamative interstitial pneumonia induced by metal exposure. A case report and literature review

Background

Forms of interstitial pneumonia secondary to exposure to an air-contaminant are varied and so far, insufficiently described.

Objectives/Methods

We report here a case of a 57-year-old patient managed in our department for the exploration of MRC grade 2 dyspnoea and interstitial pneumonia. He mentioned multiple occupational and domestic exposures such as hens' excrements, asbestos and metal particles; he also had a previous history of smoking.

Results

High-resolution computed tomography showed ground glass opacities predominating in posterior territories and surrounding cystic lesions or emphysematous destruction. The entire etiological assessment revealed only macrophagic alveolitis with giant multinucleated cells on the bronchoalveolar lavage. A surgical lung biopsy allowed us to refine the diagnosis with evidence of desquamative interstitial pneumonia and pulmonary granulomatosis. Finally, the analysis of the mineral particles in the biopsy revealed abnormally high rates of Zirconium and Aluminium. We were therefore able to conclude to a desquamative interstitial pneumonia associated with pulmonary granulomatosis linked to metal exposure (Aluminium and Zirconium). The clinical, functional and radiological evolution was favorable after a systemic corticosteroid treatment with progressive decay over one year.

Conclusion

This presentation reports the first case to our knowledge of desquamative interstitial pneumonitis related to exposure to Zirconium and the third one in the context of Aluminium exposure. The detailed analysis of the mineral particles present on the surgical lung biopsy allows for the identification of the relevant particle to refine the etiological diagnosis, to guide the therapeutic management and to give access to recognition as an occupational disease. (Sarcoidosis Vasc Diffuse Lung Dis 2020; 37 (1): 79-84).

The Occupational Burden of Nonmalignant Respiratory Diseases. An Official American Thoracic Society and European Respiratory Society Statement

Rationale: Workplace inhalational hazards remain common worldwide, even though they are ameliorable. Previous American Thoracic Society documents have assessed the contribution of workplace exposures to asthma and chronic obstructive pulmonary disease on a population level, but not to other chronic respiratory diseases. The goal of this document is to report an in-depth literature review and data synthesis of the occupational contribution to the burden of the major nonmalignant respiratory diseases, including airway diseases; interstitial fibrosis; hypersensitivity pneumonitis; other noninfectious granulomatous lung diseases, including sarcoidosis; and selected respiratory infections. Methods: Relevant literature was identified for each respiratory condition. The occupational population attributable fraction (PAF) was estimated for those conditions for which there were sufficient population-based studies to allow pooled estimates. For the other conditions, the occupational burden of disease was estimated on the basis of attribution in case series, incidence rate ratios, or attributable fraction within an exposed group. Results: Workplace exposures contribute substantially to the burden of multiple chronic respiratory diseases, including asthma (PAF, 16%); chronic obstructive pulmonary disease (PAF, 14%); chronic bronchitis (PAF, 13%); idiopathic pulmonary fibrosis (PAF, 26%); hypersensitivity pneumonitis (occupational burden, 19%); other granulomatous diseases, including sarcoidosis (occupational burden, 30%); pulmonary alveolar proteinosis (occupational burden, 29%); tuberculosis (occupational burden, 2.3% in silica-exposed workers and 1% in healthcare workers); and community-acquired pneumonia in working-age adults (PAF, 10%). Conclusions: Workplace exposures contribute to the burden of disease across a range of nonmalignant lung conditions in adults (in addition to the 100% burden for the classic occupational pneumoconioses). This burden has important clinical, research, and policy implications. There is a pressing need to improve clinical recognition and public health awareness of the contribution of occupational factors across a range of nonmalignant respiratory diseases.

Increased Pulmonary GM-CSF Causes Alveolar Macrophage Accumulation. Mechanistic Implications for Desquamative Interstitial Pneumonitis

Desquamative interstitial pneumonia (DIP) is a rare, smoking-related, diffuse parenchymal lung disease characterized by marked accumulation of alveolar macrophages (AMs) and emphysema, without extensive fibrosis or neutrophilic inflammation. Because smoking increases expression of pulmonary GM-CSF (granulocyte/macrophage-colony stimulating factor) and GM-CSF stimulates proliferation and activation of AMs, we hypothesized that chronic exposure of mice to increased pulmonary GM-CSF may recapitulate DIP. Wild-type (WT) mice were subjected to inhaled cigarette smoke exposure for 16 months, and AM numbers and pulmonary GM-CSF mRNA levels were measured. After demonstrating that smoke inhalation increased pulmonary GM-CSF in WT mice, transgenic mice overexpressing pulmonary GM-CSF (SPC-GM-CSF+/+) were used to determine the effects of chronic exposure to increased pulmonary GM-CSF (without smoke inhalation) on accumulation and activation of AMs, pulmonary matrix metalloproteinase (MMP) expression and activity, lung histopathology, development of polycythemia, and survival. In WT mice, smoke exposure markedly increased pulmonary GM-CSF and AM accumulation. In unexposed SPC-GM-CSF+/+ mice, AMs were spontaneously activated as shown by phosphorylation of STAT5 (signal inducer and activator of transcription 5) and accumulated progressively with involvement of 84% (interquartile range, 55-90%) of the lung parenchyma by 10 months of age. Histopathologic features also included scattered multinucleated giant cells, alveolar epithelial cell hyperplasia, and mild alveolar wall thickening. SPC-GM-CSF+/+ mice had increased pulmonary MMP-9 and MMP-12 levels, spontaneously developed emphysema and secondary polycythemia, and had increased mortality compared with WT mice. Results show cigarette smoke increased pulmonary GM-CSF and AM proliferation, and chronically increased pulmonary GM-CSF recapitulated the cardinal features of DIP, including AM accumulation, emphysema, secondary polycythemia, and increased mortality in mice. These observations suggest pulmonary GM-CSF may be involved in the pathogenesis of DIP.

Aluminium toxicosis: a review of toxic actions and effects

Aluminium (Al) is frequently accessible to animal and human populations to the extent that intoxications may occur. Intake of Al is by inhalation of aerosols or particles, ingestion of food, water and medicaments, skin contact, vaccination, dialysis and infusions. Toxic actions of Al induce oxidative stress, immunologic alterations, genotoxicity, pro-inflammatory effect, peptide denaturation or transformation, enzymatic dysfunction, metabolic derangement, amyloidogenesis, membrane perturbation, iron dyshomeostasis, apoptosis, necrosis and dysplasia. The pathological conditions associated with Al toxicosis are desquamative interstitial pneumonia, pulmonary alveolar proteinosis, granulomas, granulomatosis and fibrosis, toxic myocarditis, thrombosis and ischemic stroke, granulomatous enteritis, Crohn's disease, inflammatory bowel diseases, anemia, Alzheimer's disease, dementia, sclerosis, autism, macrophagic myofasciitis, osteomalacia, oligospermia and infertility, hepatorenal disease, breast cancer and cyst, pancreatitis, pancreatic necrosis and diabetes mellitus. The review provides a broad overview of Al toxicosis as a background for sustained investigations of the toxicology of Al compounds of public health importance.

Metal-Induced Pulmonary Fibrosis

PURPOSE OF REVIEW

The incidence of pulmonary fibrosis is increasing worldwide and may, in part, be due to occupational and environmental exposures. Secondary fibrotic interstitial lung diseases may be mistaken for idiopathic pulmonary fibrosis with important implications for both disease management and prognosis. The purposes of this review are to shed light on possible underlying causes of interstitial pulmonary fibrosis and to encourage dialogue on the importance of acquiring a thorough patient history of occupational and environmental exposures.

RECENT FINDINGS

A recent appreciation for various occupational and environmental metals inducing both antigen-specific immune reactions in the lung and nonspecific "innate" immune system responses has emerged and with it a growing awareness of the potential hazards to the lung caused by low-level metal exposures. Advancements in the contrast and quality of high-resolution CT scans and identification of histopathological patterns of interstitial pulmonary fibrosis have improved clinical diagnostics. Moreover, recent findings indicate specific hotspots of pulmonary fibrosis within the USA. Increased prevalence of lung disease in these areas appears to be linked to occupational/environmental metal exposure and ethnic susceptibility/vulnerability. A systematic overview of possible occupational and environmental metals causing interstitial pulmonary fibrosis and a detailed evaluation of vulnerable/susceptible populations may facilitate a broader understanding of potential underlying causes and highlight risks of disease predisposition.

Coal Mine Dust Desquamative Chronic Interstitial Pneumonia: A Precursor of Dust-Related Diffuse Fibrosis and of Emphysema

Background:

Diseases associated with coal mine dust continue to affect coal miners. Elucidation of initial pathological changes as a precursor of coal dust-related diffuse fibrosis and emphysema, may have a role in treatment and prevention.

Objective:

To identify the precursor of dust-related diffuse fibrosis and emphysema.

Methods:

Birefringent silica/silicate particles were counted by standard microscope under polarized light in the alveolar macrophages and fibrous tissue in 25 consecutive autopsy cases of complicated coal worker's pneumoconiosis and in 21 patients with tobacco-related respiratory bronchiolitis.

Results:

Coal miners had 331 birefringent particles/high power field while smokers had 4 (p<0.001). Every coal miner had intra-alveolar macrophages with silica/silicate particles and interstitial fibrosis ranging from minimal to extreme. All coal miners, including those who never smoked, had emphysema. Fibrotic septa of centrilobular emphysema contained numerous silica/silicate particles while only a few were present in adjacent normal lung tissue. In coal miners who smoked, tobacco-associated interstitial fibrosis was replaced by fibrosis caused by silica/silicate particles.

Conclusion:

The presence of silica/silicate particles and anthracotic pigment-laden macrophages inside the alveoli with various degrees of interstitial fibrosis indicated a new disease: coal mine dust desquamative chronic interstitial pneumonia, a precursor of both dust-related diffuse fibrosis and emphysema. In studied coal miners, fibrosis caused by smoking is insignificant in comparison with fibrosis caused by silica/silicate particles. Counting birefringent particles in the macrophages from bronchioalveolar lavage may help detect coal mine dust desquamative chronic interstitial pneumonia, and may initiate early therapy and preventive measures.

A case of mixed dust pneumoconiosis with desquamative interstitial pneumonia-like reaction in an aluminum welder

A 60-year-old man presented with an 18-month history of gradually worsening cough and a 12-month history of dyspnea on exertion. High-resolution computed tomography showed bilateral uniform ground grass opacity in the lower lung fields, partially resolved by smoking cessation. A tentative diagnosis of desquamative interstitial pneumonia (DIP) was made. Video-assisted thoracic surgery was performed and pathological analysis showed peribronchiolar fibrosis with intra-alveolar macrophage infiltration. Elemental analysis detected aluminum and iron in the upper lobe and only iron in the lower lobe. Thus, a definitive diagnosis of mixed dust pneumoconiosis with DIP-like reaction was made. DIP-like reaction is known to be a reactive change caused by exposure to tobacco smoke as well as by inhalation of inorganic particles. Obtaining a detailed medical history including occupational and environmental risk factors is important to distinguish cases of DIP-like reaction due to exposure to inorganic particles from the usual cases related to smoking, and thus provide suitable treatment.

Pulmonary fibrosis and exposure to steel welding fume

BACKGROUND

Arc welders who have been exposed to high concentrations of steel welding fume for prolonged periods of time may develop pulmonary fibrosis but the nature of the fibrotic changes has been debated over the last 80 years without any clear international consensus.

AIMS

To characterize the nature of the pulmonary fibrosis that develops in response to steel welding fume exposure and to provide a working hypothesis that would explain the findings of the existing research, to provide a platform for future research and to inform future occupational and clinical management of welders with pulmonary effects from welding fume.

METHODS

Review of the world literature on pulmonary fibrosis and welding of steel in all languages using PubMed, with further secondary search of references in the articles found in the primary search. Google and Reference Manager were used as further confirmatory search tools.

RESULTS

Only case series and case reports were found but these provided consistent evidence that the consequence of exposure to steel welding fume at high levels for a prolonged period of time is a type of pulmonary fibrosis similar to, and possibly the same as, respiratory bronchiolitis which eventually develops into desquamative interstitial pneumonia with ongoing exposure.

CONCLUSIONS

Steel welding fume may cause an occupational respiratory bronchiolitis which may develop into de squamative interstitial pneumonia with ongoing exposure. This concept may explain the difficulties in interpreting the wider literature on welding fume and lung function at lower exposures and may also explain the increased risk of lung cancer in welders.

Smoking-related idiopathic interstitial pneumonia: A review

For many years, cigarette smoking has been considered as the leading cause of chronic obstructive pulmonary disease and lung cancer. Recently, however, it has also been associated with the development of diffuse interstitial lung diseases. In the latest classification of the major idiopathic interstitial pneumonias (IIP), the term smoking-related IIP has been introduced, including two entities, namely desquamative interstitial pneumonia (DIP) and respiratory bronchiolitis-interstitial lung disease (RB-ILD). Other entities in which smoking has a definite or suggested role include pulmonary Langerhan's cell histiocytosis, smoking-related interstitial fibrosis, combined pulmonary fibrosis and emphysema syndrome and idiopathic pulmonary fibrosis. In this review, we will focus on the mechanisms of smoking-related lung damage and on the clinical aspects of these disorders with the exception of idiopathic pulmonary fibrosis, which will be reviewed elsewhere in this review series.

Diffuse parenchymal diseases associated with aluminum use and primary aluminum production

Aluminum use and primary aluminum production results in the generation of various particles, fumes, gases, and airborne materials with the potential for inducing a wide range of lung pathology. Nevertheless, the presence of diffuse parenchymal or interstitial lung disease related to these processes remains controversial. The relatively uncommon occurrence of interstitial lung diseases in aluminum-exposed workers--despite the extensive industrial use of aluminum--the potential for concurrent exposure to other fibrogenic fibers, and the previous use of inhaled aluminum powder for the prevention of silicosis without apparent adverse respiratory effects are some of the reasons for this continuing controversy. Specific aluminum-induced parenchymal diseases described in the literature, including existing evidence of interstitial lung diseases, associated with primary aluminum production are reviewed.

A 26-Year-Old Welder with Severe Non-Reversible Obstructive Lung Disease

A 26-year-old white male, lifelong non-smoker presented with a history of increased shortness of breath, for approximately 1 year. He had a history of welding aluminum parts. He had evidence of partially reversible reactive airways disease with a non obstructive component as well. VATS biopsy revealed evidence of airway and parenchymal inflammation consistent with aluminum pneumoconiosis. Approximately 5-10% of COPD is attributable to non-smoking causes including occupational exposures. There are studies to suggest that the persistence of aluminum particulate may cause ongoing inflammation despite removal from exposure. It is possible that the persistence of particulate matter from tobacco smoke remaining in the lung may contribute to the persistent inflammatory response found in former smokers. Further study is required to examine the importance of this potential inflammatory mechanism both in occupationally exposed and in cigarette smokers. Reduction of certain particulate components of cigarette smoke may have implications for prevention of disease or at least disease progression in some COPD patients.

Histiocytic lesions and proliferations in the lung

Pulmonary lesions encountered by the pathologist in which histiocytes are the dominant finding histologically are reviewed. Lesions discussed include neoplasms of histiocytes and nonneoplastic processes. The nonneoplastic processes are divided into those that present as nodular histiocytic proliferations in the lung, those that present as diffuse proliferations of histiocytes in the lung, and those with a mixed pattern. Entities discussed include pulmonary Langerhans' cell histiocytosis, pneumonoconioses, infections, diffuse panbronchiolitis, crystal storing histiocytosis, respiratory bronchiolitis, alveolar hemorrhage, eosinophilic pneumonia, obstructive pneumonia, exogenous lipoid pneumonia, some drug reactions, and some metabolic/storage diseases. Entities of uncertain histogenesis, including Rosai-Dorfman disease and Erdheim-Chester disease, are also discussed. Qualitative features of the histiocytes are addressed, including the presence of foreign dust, hemosiderin, foamy change, and histiocytes showing features of Langerhans' cells.

Current concepts in the classification of interstitial lung disease

The diagnosis and classification of idiopathic interstitial pneumonias continue to be problematic areas for pathologists. The recently proposed American Thoracic Society/European Respiratory Society International Multidisciplinary Consensus Classification of the Idiopathic Interstitial Pneumonias defines specific clinical, radiologic, and pathologic criteria for each of the pulmonary disorders that encompass the idiopathic interstitial pneumonias. In this review, the highlights of this classification are presented, along with recommended guidelines for handling lung biopsy specimens and diagnosing interstitial lung diseases.

Role of Thoracic Surgeons in the Diagnosis of Idiopathic Interstitial Lung Disease

The interstitial lung disorders are a heterogenous group of pulmonary disorders in which the interstitium is the predominant tissue type involved in the disease process. The idiopathic interstitial pneumonias represent a subgroup of these disorders that can be distinguished by unique clinical, radiologic, and pathologic features. Recent changes have been made in the classification system, with important distinctions between idiopathic pulmonary fibrosis and the other idiopathic interstitial pneumonias. Surgical lung biopsy remains the gold standard for diagnosis. However, controversy exists regarding the methods and indications for biopsy. In this article, we review the salient clinical, radiologic, and pathologic features of these unique disorders as well as the updated classification scheme. We also discuss the current methods, approaches, and indications for biopsy.

Neurologic manifestations in welders with pallidal MRI T1 hyperintensity

BACKGROUND

Neurologic symptoms have been attributed to manganese fumes generated during welding. Increased T1 MRI signal in the basal ganglia is a biologic marker of manganese accumulation. Recent studies have associated welding and parkinsonism, but generally without MRI corroboration.

OBJECTIVE

To characterize the clinical and neuropsychological features of patients with MRI basal ganglia T1 hyperintensity, who were ultimately diagnosed with neurotoxicity from welding fumes.

METHODS

The medical records of welders referred to the Department of Neurology with neurologic problems and basal ganglia T1 hyperintensity were reviewed.

RESULTS

All eight patients were male career welders with increased T1 basal ganglia signal on MRI of the brain. Several different clinical syndromes were recognized: a parkinsonian syndrome (three patients), a syndrome of multifocal myoclonus and limited cognitive impairment (two patients), a mixed syndrome with vestibular-auditory dysfunction (two patients), and minor subjective cognitive impairment, anxiety, and sleep apnea (one patient). Neuropsychometric testing suggested subcortical or frontal involvement. Inadequate ventilation or lack of personal respiratory protection during welding was a common theme.

CONCLUSIONS

Welding without proper protection was associated with syndromes of parkinsonism, multifocal myoclonus, mild cognitive impairment, and vestibular-auditory dysfunction. The MRI T1 hyperintensity in the basal ganglia suggests that these may have been caused by manganese neurotoxicity.

[DIP (desquamative interstitial pneumonia): as a tobacco-associated disease -- case report]

DIP (desquamative interstitial pneumonia) is an interstitial lung disease with diffuse and uniform accumulation of alveolar macrophages. There is a strong association with tobacco since 90% of the patients are smokers. The interstitial lung diseases related to tobacco are diverse and include tumours, emphysema, chronic bronchitis, RBILD (Respiratory Bronchilites associated Interstitial Lung Disease), DIP and Langerhans Cell Histiocitosis. The authors present a case of DIP. A brief theorycal revision and discussion of a case is made facing the association with tobacco.

Classification of idiopathic interstitial pneumonias: making sense of the alphabet soup

Since Liebow and Carrington's original classification of idiopathic interstitial pneumonias, there have been controversies over which histological patterns should be included and how they relate to clinicopathological diseases such as cryptogenic fibrosing alveolitis/idiopathic pulmonary fibrosis (CFA/IPF). Because of these differences and the wealth of overlapping terminology, a consensus classification system has been proposed, devised by a group of clinicians, radiologists and pathologists. Seven histological patterns are recognized: usual interstitial pneumonia (UIP), non-specific interstitial pneumonia (NSIP), diffuse alveolar damage (DAD), organizing pneumonia (OP), desquamative interstitial pneumonia (DIP), respiratory bronchiolitis (RB) and lymphocytic interstitial pneumonia (LIP), each with a clinicopathological counterpart, the most well defined being UIP and CFA/IPF. The system is applicable both in terms of the pathologist identifying histological patterns in isolation and in terms of the pathologist's role in contributing to the final clinicopathological diagnosis. It will probably provide greater consistency in diagnosis, early studies suggesting that the system is reproducible, and also identify purer cohorts for studies investigating causation. It also highlights the fact that the 'gold standard for diagnosis' is no longer a surgical lung biopsy in isolation but more the clinicopathological conference, when clinical, imaging and histological data are jointly discussed to produce the final clinicopathological diagnosis.

Aluminum welding fume-induced pneumoconiosis

Chronic exposure to high concentrations of fumes during aluminum arc welding causes a severe pneumoconiosis characterized by diffuse pulmonary accumulation of aluminum metal and a corresponding reduction in lung function. Aluminum fume-induced pneumoconiosis is a rarely reported entity, of which the true incidence is unknown. We report the clinical, radiographic, microscopic, and microanalytic results of 2 coworkers, employed by the same aluminum shipbuilding facility, who died of complications from this disease. Scanning electron microscopy and energy dispersive x-ray analysis of the exogenous particle content in the lung tissue of these cases revealed the highest concentrations of aluminum particles (average of 9.26 billion aluminum particles per cm(3) of lung tissue) among the 812 similar analyses in our pneumoconiosis database. One patient had an original clinical diagnosis of sarcoidosis but no evidence of granulomatous inflammation.

High-resolution CT in the evaluation of occupational and environmental disease

The most common of the pneumoconioses are silicosis, CWP, and asbestosis. The former two are characterized by the presence of small nodular opacities predominantly distributed in the upper zones of the lung. The small nodular opacities are classified into two patterns on HRCT: (1) ill-defined fine branching lines and (2) well-defined discrete nodules. Asbestosis demonstrates thickened interlobular and intralobular lines, subpleural dot-like or curvilinear opacities, and honeycombing on HRCT, predominantly distributed in the bases of the lungs. Although HRCT findings of other pneumoconioses are variable and nonspecific, there are predominant and characteristic findings for each type of pneumoconiosis. HRCT is useful in achieving more accurate categorization of the parenchymal changes in each type of pneumoconiosis.

Analysis and interpretation of inorganic mineral particles in "lung" tissues

Mineral analysis of tissue specimens has provided very useful information in pathological conditions associated with occupational exposures to mineral particles, particularly when combined with epidemiological information. Most of the data have been related to exposures to fibrous particles such as asbestos. More investigations of this nature are required in diseases associated with exposure to non-fibrous particles. In the future it is likely that these types of investigation will be extended into the effects of pollutants.

X-ray microanalysis of peripheral lung carcinomas

A total of 15 cases of peripherally located lung carcinomas associated with scar (scar carcinoma) were studied by light microscopy and electron microscopy with energy-dispersive X-ray microanalysis (XMA). Results were compared to those of three autopsy lungs without significant pulmonary findings that served as controls. Fibrosis with scar formation characterized the 15 tumor cases. Particulate depositions including doubly refractile particles were also increased in the tumor group. XMA identified 25 elements with great complexity of particulate composition. Silicon was the most prominent element and was found in 16 of 18 cases studied. Kaolinite, feldspar, talc, muscovite, and silica were recognized. The fibrogenic properties of silicate compounds were emphasized, including their prominence in the lung tumor group. While the important concept of tumor desmoplasia was recognized, the study showed significant fibrosis in relation to fibrogenic materials, which undoubtedly preceded the appearance of the tumors. Also noted were the carcinogens uranium, cadmium, chromium, nickel, and arsenic, some of which were previously described as minor constituents of naturally occurring minerals.

Hypersensitivity pneumonitis presenting as sarcoidosis

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Irregular opacities in the lung, occupational asthma, and airways dysfunction in aluminum workers

We examined chest X-rays, measured expiratory flows and FVC by spirometry and TLC by projected lung area, ascertained respiratory data by questionnaires, and performed chest examinations in 670 Southeastern aluminum workers and 659 unexposed regional controls. Both groups were asbestos exposed. More aluminum workers had irregular opacities and fewer had pleural abnormalities than did regional pipefitter referents. The pulmonary function tests were expressed as percentage of predicted to adjust for height, age and duration of smoking based on a randomly selected U.S. reference population. Data from aluminum workers were compared to regional controls with students "t" tests run for unequal size groups. Aluminum workers had significant reductions in FEV1 of 3.2% predicted (p less than .003), FEF25-75 of 11.3% predicted (p less than .0001), FEF75-85 of 22.5% predicted (p less than .0001), and an increased TLC of 2.0% predicted (p less than .005). The 145 who had never smoked (NS) were compared with 124 NS controls and showed this same pattern of differences; but in smokers, the differences were significant for mid and terminal flows, but not for FEV1. In aluminum workers who never smoked, asthma prevalence by history was 7.6% vs. 4.0% in controls, and wheezes were heard in 21.4% vs. 2.4% in controls. In aluminum workers who were current smokers, asthma prevalence was 16.4% vs. 9.4% in controls, and wheezes were heard in 43.7% vs. 21.1% in controls. Aluminum workers had significantly more asthma, wheezing, airways obstruction, and pulmonary parenchymal abnormalities similar to asbestosis than did regional blue collar controls not melting and casting aluminum.

Histopathologic findings and energy dispersive X-ray spectroscopic analysis of experimentally induced foreign-body pneumonias in rats

To document the diagnostic features of foreign-body pneumonias, four commonly used orally administered medicaments were instilled into the lungs of Sprague-Dawley rats. Rats in each group received a single 0.4 ml dose of either barium sulfate suspension (BaSO4), mineral oil, Pepto-bismol, or Kaopectate inoculated into a lung via a mainstem bronchus. The other lung served as a non-inoculated control. Rats were euthanatized on post-inoculation day 2 or 7 in order to document fully-developed acute pulmonary lesions and developing, chronic pulmonary lesions, respectively. Light microscopic features of BaSO4-inoculated lungs were distinctive from changes in mineral oil-inoculated lungs at both post-inoculation days. On post-inoculation day 2, rats inoculated with BaSO4 had pneumonia characterized by large numbers of alveolar macrophages containing green-to-brown granular material. There was minimal interstitial involvement. On post-inoculation day 2, mineral oil caused pneumonia characterized by giant cells and alveolar macrophages that had cytoplasms distended with variably-sized clear vacuoles. Lungs inoculated with BaSO4 or mineral oil had changed little on post-inoculation day 7 compared to the light microscopic features observed on day 2. On post-inoculation day 2, rats inoculated with either Pepto-bismol or Kaopectate had broncho-interstitial pneumonia with areas of necrosis and hemorrhage. On post-inoculation day 7, lungs inoculated with Pepto-bismol or Kaopectate had extensive fibrosis within alveolar lumens. Energy dispersive spectroscopy performed on sections of lung from rats given BaSO4, Pepto-bismol, and Kaopectate yielded a unique elemental spectrum for each compound in situ on post-inoculation days 2 and 7.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum and chronic renal failure: sources, absorption, transport, and toxicity

In normal subjects the gastrointestinal tract is a relatively impermeable barrier to aluminum with a low fractional absorption rate for this metal ion. Aluminum absorbed from the gastrointestinal tract is normally excreted by the kidneys; in the presence of impaired renal function aluminum is retained and accumulates in body tissues. Aluminum-containing medications are given, by mouth, to patients with chronic renal failure as phosphate-binding agents for the therapeutic control of hyperphosphatemia. Patients with chronic renal failure are also exposed to aluminum in domestic tap-water supplies used either for drinking or, in those on dialysis treatment, in the preparation of their dialysate. In patients with end-stage chronic renal failure, particularly in those on treatment by hemodialysis, the accumulation of aluminum in bone, brain, and other tissues is associated with toxic sequelae. An increased brain content of aluminum appears to be the major etiological factor in the development of a neurological syndrome called either "dialysis encephalopathy" or "dialysis dementia"; an increased bone content causes a specific form of osteomalacia. An excess of aluminum also appears to be an etiological factor in a microcytic, hypochromic anemia that occurs in some patients with chronic renal failure on long-term treatment with hemodialysis. The various mechanisms involved in the toxic phenomena associated with the accumulation of aluminum in body tissues have not been clearly defined but are the subject of extensive investigations.

Deposition of bauxite dust and pulmonary fibrosis

In a 70 years old worker in the bauxite industry in Surinam, who died of myocardial infarction, bauxite deposits were found in the lung in areas of mild pulmonary fibrosis. The identification and the localization within these areas of the bauxite deposits was determined by a histochemical mineralization technique and by scanning electron microscopy and electron microprobe analysis. The possible relationship between the presence of bauxite in the lung tissue and the pulmonary fibrosis is discussed.

Mineral dusts in lungs with scar or scar cancer

Five lungs with small scars and five lungs with small scar associated cancers, were studied by light and scanning electron microscopy and x-ray energy dispersive spectrometry. Six hundred particles were photographed and their physical and chemical properties analyzed from scar, cancer, or normal alveolar tissue on carbon planchet-mounted, deparaffinized and low temperature-ashed sections. Amosite/crocidolite fibers were accumulated only in one cancerous lung. All other lungs shared similar types of mineral particles. The lungs with noncancer scars, however, showed an increase in the ratio of aluminum and calcium salts (non-silicates), while the lungs with scar cancers had a higher ratio of silicates. These patterns of particle distribution were similar in different areas of the same lung, despite the fact mechanism is unclear, these results are consistent with the possibility that the pattern of mineral particle distribution in a lung may influence the formation of cancer in a scar.

Interstitial lung disease and asthma in hard-metal workers: bronchoalveolar lavage, ultrastructural, and analytical findings and results of bronchial provocation tests

Five patients with respiratory disorders associated with hard metal exposure are described. In four patients electron microprobe analysis of bronchoalveolar lavage cells or lung tissue was used to show tungsten and other hard-metal components. Three patients had interstitial pneumonia and fibrosis with unusual multinucleate giant cells. Electron microscopy showed that the giant cells comprised both type II alveolar epithelial cells and alveolar macrophages. The multinucleate macrophages formed a distinctive feature of the bronchoalveolar lavage material but the multinucleate alveolar epithelial lining cells were evident only in lung tissue. The other two patients both suffered from work-related asthma, one of whom also had pulmonary opacities. Bronchial provocation tests in these patients supported the diagnosis of hard-metal-induced asthma and implicated cobalt as the agent responsible.