Pneumoconiosis: comparison of imaging and pathologic findings

Pulmonary Calcification and Ossification: Pathogenesis, CT Appearance, and Specific Disorders

Pulmonary high attenuation may be caused by calcification or ossification, both of which are common phenomena with distinct pathogeneses, histologies, and radiologic appearances. Pulmonary calcification is divided into metastatic pulmonary calcification (MPC), caused by systemic hypercalcemia, and dystrophic pulmonary calcification (DPC), caused by local lung injury. MPC often demonstrates diffuse calcified nodules, which can be subtle and amorphous on CT images, with associated sandlike, fine ground-glass, or consolidative opacities. Conversely, DPC often appears nodular and is localized to areas of lung injury and thus is associated with other signs of lung damage, such as prior infection, fibrosis, or scarring. In contrast to calcification, pulmonary ossification is not a consequence of a localized or systemic metabolic abnormality but instead is found in the setting of chronic lung disease, which induces fibroblast-to-osteoblast transformation and bone deposition. Pulmonary ossification can be divided into nodular (NPO) and dendriform (DPO) patterns. NPO often appears as multiple small well-defined round nodules that are uniform in size and appearance. NPO classically is seen with chronic venous congestion in a subpleural predominant distribution and increasingly is recognized in pathologic findings in the setting of fibrosing interstitial lung disease (ILD). DPO appears more commonly as peripheral irregular branching opacities and can be seen with ILD. Additionally, pulmonary calcification or ossification can occur in association with protein deposition disease, including pulmonary amyloidosis, or in benign neoplasms or metastatic malignancies. Pulmonary alveolar microlithiasis is a distinct entity relating to phosphate metabolism. Pulmonary calcification and ossification can provide insight into patients' underlying disease processes and clinical context for radiologic study interpretation. ©RSNA, 2025 Supplemental material is available for this article.

Fibrotic pulmonary dust foci is an advanced pneumoconiosis lesion in rats induced by titanium dioxide nanoparticles in a 2-year inhalation study

BACKGROUND

We have previously reported that inhalation exposure to titanium dioxide nanoparticles (TiO2 NPs) for 13 weeks causes early pneumoconiosis lesions in the alveolar region of F344 rats. We defined these characteristic lesions as pulmonary dust foci (PDF). In this report, we re-evaluate and detail the histopathological data regarding particle-induced pneumoconiosis lesions, including progressive lesions of the early PDF lesions, that developed in F344 rats exposed TiO2 NPs by whole body inhalation over a period of two years.

METHODS

Male and female F344 rats were exposed to 0.5, 2, and 8 mg/m3 anatase type TiO2 NPs for 6 h/day, 5 days/week for 104 weeks using a whole-body inhalation exposure system. After the final exposure, the rats were euthanized. In the present study, the collected lungs were re-evaluated macroscopically and histopathologically.

RESULTS

Rats exposed to TiO₂ NPs developed macroscopic white lesions, primarily in the subpleural and hilar regions of the lung, which increased in size and number with exposure concentration. Histologically, two lesion types were identified: (1) Fibrotic Pulmonary Dust Foci (fPDF), characterized by collagen deposition, inflammatory infiltration, and disrupted alveolar epithelial differentiation, and (2) Dust Macules (DM), characterized by macrophage accumulation without significant fibrosis or inflammation. fPDFs, but not DMs, were observed after 13 weeks exposure to TiO₂ NPs, indicating that the DM-type pneumoconiosis lesions required a longer time to develop compared to fPDF-type pneumoconiosis lesions. Histopathological analysis revealed that the DM-type pneumoconiosis lesions that developed in rats exposed to TiO₂ NPs were similar to DM-type pneumoconiosis lesions that develop in humans.

CONCLUSIONS

Inhalation exposure to TiO₂ NPs caused the development of two types of pneumoconiosis lesions in rats with distinct pathological features, fPDFs and DMs. The histopathological similarity of the DM-type pneumoconiosis lesions that developed in rat lung in the present study with the DM-type pneumoconiosis lesions that develop in the human lung adds strong support to the conclusion that humans exposed to airborne TiO₂ NPs are at risk of developing pneumoconiosis.

A 57-Year-Old Man With Persistent Miliary Pattern Pulmonary Nodules and New Lung Masses on Chest CT Scan

CASE PRESENTATION

A 57-year-old man presented to the hospital with a 6-year history of slowly progressive persistent cough, shortness of breath, and wheezing. He had been prescribed budesonide and oxygen therapy 2 months prior for presumable asthma, but his symptoms had not subsided. He had been intermittently using 2 L oxygen via nasal canula with exertional activities until the day of hospitalization. He first experienced similar symptoms 5 years prior, and a workup at that time showed multiple tiny pulmonary nodules. His history was notable for a remote 27-pack-year smoking history, quitting 10 years prior, and he was diagnosed with asthma 2 years before his presentation. His occupational history included 17 years working in Israel with polished granite, quartz, and artificial marble. He denied exposure to asbestos, beryllium, radon, or chemicals, aluminum, semiconductors, dental materials, cosmetic powders, or talc. The patient denied environmental exposures such as black mold, hot tubs, or birds. Preceding our assessment, the patient had undergone a chest CT scan 6 years prior, revealing profound chronic alterations in the pulmonary architecture alongside mediastinal adenopathy. Three of his previous chest CT scans found numerous nodules of varying sizes throughout both lung fields, which had remained relatively stable over the years.

What rationale for treatment of occupational interstitial lung diseases with the drugs approved for idiopathic pulmonary fibrosis?

PURPOSE OF REVIEW

To critically discuss the rationale for the use of drugs approved for idiopathic pulmonary fibrosis (IPF) to treat occupational interstitial lung diseases (OILDs).

RECENT FINDINGS

Although IPF and OILDs share several clinical, radiological and probably pathogenetic features, currently, OILDs do not have a standard of care. In recent years, our knowledge and understanding of ILDs has improved substantially. Recently, the progressive pulmonary fibrosis (PPF) phenotype, which refers to non-IPF fibrotic ILDs that progress despite appropriate treatment, has been defined. OILDs may also be progressive. Nintedanib, initially approved for treatment of IPF, is also approved in patients with PPF. On the other hand, pirfenidone is approved in IPF but not in PPF, due to the lack of robust evidence of efficacy in this patient subset.

SUMMARY

OILDs are a large and highly heterogeneous group of conditions without a proper standard of care. Nintedanib may slow functional decline and disease progression in progressive OILDs, and new clinical trials are ongoing.

New insights into imaging of pulmonary metastases from extra-thoracic neoplasms

The lung is one of the most common sites of metastases from extra-thoracic neoplasms. Lung metastases can show heterogeneous imaging appearance, thus mimicking a wide range of lung diseases, from benign lesions to primary lung cancer. The proper interpretation of pulmonary findings is crucial for prognostic assessment and treatment planning, even to avoid unnecessary procedures and patient anxiety. For this purpose, computed tomography (CT) is one of the most used imaging modalities. In the last decades, cancer patients' population has steadily increased and, due to the widespread application of CT for staging and surveillance, the detection of pulmonary nodules has raised, making their characterization and management an urgent and mostly unsolved problem for both radiologists and clinicians. This review will highlight the pathways of dissemination of extra-thoracic tumours to the lungs and the heterogeneous CT imaging appearance of pulmonary metastases, providing useful clues to properly address the diagnosis. Furthermore, we will deal with the promising applications of radiomics in this field. Finally, a focus on the hot-topic of pulmonary nodule management in patients with extra-thoracic neoplasms (ETNs) will be discussed.

Pulmonary Artery Stent Implantation for Fibrosing Mediastinitis: Our Clinical Experience

Fibrosing mediastinitis (FM) can block pulmonary vessels and airways, hindering treatment efficacy. Pulmonary artery (PA) stenting might provide a solution in such cases. This study involved 30 patients who had 49 PA stenting procedures for FM. Data on baseline characteristics, CT pulmonary angiography images, stent patency, and hemodynamics were collected. Patients with FM often had a history of chronic obstructive pulmonary disease (15/30), tuberculosis (12/30), and pneumoconiosis (11/30). Patients exhibited typical symptoms such as dyspnea, exercise intolerance, and cough. FM appeared as multiple bilateral shadows with enlarged hilar and mediastinal lymph nodes. Our study found that the PA involvement alone was predominantly in the left and right lower basilar trunk, with the left lower pulmonary arteries (LLPA) involved in 80% of cases and the right lower pulmonary arteries (RLPA) in 100%. Moreover, over 2/3 of patients showed involvement of both PA and pulmonary vein (PV), mainly in the bilateral upper lung lobes, then in the right middle lobe and left lingual lobe. After PA stent implantation, patients showed enhanced tricuspid annular plane systolic excursion (20.6 vs. 18.5, p < 0.001) and reduced right atrial diameter (35.5 vs. 37.3, p = 0.042), along with significant gains in 6-min walk distance (465.2 vs. 392.7, p = 0.002) and improved World Health Organization functional class (p < 0.001). Hemodynamic parameters improved after PA stent placement with significant reductions in systolic pulmonary artery pressure (PAP) (51.1 vs. 64.2, p < 0.001), mean PAP (28.4 vs. 35.2, p < 0.001), pulmonary vascular resistance (4.7 vs. 5.9, p = 0.004), and stent gradient (11.2 vs. 33.4, p < 0.001), along with increased patency (84.8% vs. 28%, p < 0.001), and fractional flow reserve (0.84 vs. 0.44, p < 0.001). Over a median follow-up of 331 days (range 45-980), no significant stent stenosis occurred (p = 0.287). Mild adverse events like cough and mild hemoptysis were noted during the procedure. Secondary intervention was needed for 5 of 49 stents. PA stents placement, especially the LLPA and RLPA, improved pulmonary vascular patency, hemodynamics, and symptoms.

A review of silicosis and other silica-related diseases in the engineered stone countertop processing industry

BACKGROUND

Engineered stone (ES), a material that has become widespread for its use in kitchen and bathroom countertops since the 1980s, is composed of over 90% crystalline silica by weight, significantly exceeding the silica content of natural stones such as granite (40-50%) and marble (< 10%). Workers fabricating ES are exposed to dangerously high levels of respirable crystalline silica (RCS) and other toxic chemicals, which increases the risk of developing silicosis and other lung and systemic diseases. The purpose of this review is to explore the epidemiology, occupational risks, regulatory gaps, diagnostic evaluation, and clinical challenges associated with ES dust exposure.

MAIN BODY

ES silicosis was first described in the early 2010s among ES countertop workers in Spain, Italy, and Israel. Since then, hundreds of cases have emerged worldwide, namely in China, Australia, the United States, the United Kingdom, and Belgium. Silicosis from ES dust is accelerated and diagnosed after 7-19 years of exposure, often affecting young individuals (median age 33-55 years) from marginalized or immigrant communities. Morbidity and mortality are poor, with high rates of lung transplantation and death. Industrial hygiene air sample monitoring data shows that despite engineering controls such as wet saws and exhaust ventilation, exposure to respirable crystalline silica when cutting ES frequently exceeds safe exposure levels. Diagnostic evaluation and treatment are clinically challenging due to delayed medical screening, misdiagnosis, and lack of treatment options.

CONCLUSIONS

This review underscores the urgent need for enhanced occupational safety regulations, active screening, and healthcare support to address the rising burden of ES silicosis among vulnerable worker populations globally.

Calcified Lung Nodules: A Diagnostic Challenge in Clinical Daily Practice

Calcified lung nodules are frequently encountered on chest imaging, often as incidental findings. While calcifications are typically associated with benign conditions, they do not inherently exclude malignancy, making accurate differentiation essential. The primary diagnostic challenge lies in distinguishing benign from malignant nodules based solely on imaging features. Various calcification patterns, including diffuse, popcorn, lamellated and eccentric, provide important diagnostic clues, though overlap among different conditions may persist. A comprehensive diagnostic approach integrates clinical history with multimodal imaging, including magnetic resonance and nuclear medicine, when necessary, to improve accuracy. When imaging findings remain inconclusive, tissue sampling through biopsy may be required for definitive characterization. This review provides an overview of the imaging features of calcified lung nodules, emphasizing key diagnostic challenges and their clinical implications.

A mechanistic review-regulation of silica-induced pulmonary inflammation by IL-10 and exacerbation by Type I IFN

Occupational exposure to crystalline silica (CS) is known to induce silicosis, a chronic lung disease characterized by the formation of granulomas and severe lung fibrosis. Specifically, individuals exposed to low doses of CS may develop silicosis after a decade or more of exposure. Similarly, in rat silicosis models exposed to occupationally relevant doses of α-quartz, there is an initial phase characterized by minimal and well-controlled pulmonary inflammation, followed by the development of robust and persistent inflammation. During the initial phase, the inflammation provoked by α-quartz is subdued by two mechanisms. Firstly, α-quartz particles are engulfed by alveolar macrophages (AMs) of the alternatively activated (M2) subtype and interstitial macrophages (IMs), limiting their interaction with other lung cells. Secondly, the anti-inflammatory cytokine, interleukin (IL)-10, is constitutively expressed by these macrophages, further dampening the inflammatory response. In the later inflammatory phase, IL-10-dependent anti-inflammatory state is disrupted by Type I interferons (IFNs), leading to the production of pro-inflammatory cytokines in response to α-quartz, aided by lipopolysaccharides (LPS). This review delves into the complex pathways involving IL-10, LPS, and Type I IFNs in α-quartz-induced pulmonary inflammation, offering a detailed analysis of the underlying mechanisms and identifying areas for future research.

Risk factors for silicotuberculosis among miners: a scoping review

BACKGROUND

Miners exposed to silica dust are susceptible to silicotuberculosis (STB) outcome - the development of tuberculosis (TB) in miners with silicosis. STB is an important occupational and public health issue in the twenty-first century. This scoping review aimed to map the risk factors associated with STB.

METHODS

A literature search was carried out to identify the available international literature on STB risk factors from four databases: MEDLINE, EMBASE, CINAHL, and COCHRANE LIBRARY. Various grey literature sources such as Google Scholar, Science.gov, and WHO Global Index Medicus were also searched. The main study outcome is STB; the selection criteria also included studies assessing TB and silicosis as comorbidities leading to STB.

RESULTS

The final review included 22 studies. Findings identified various STB risk factors including demographic factors such as age and sex, lifestyle factors including smoking and alcohol intake, clinical factors such as history of TB, grades of silicosis, and human immunodeficiency virus (HIV), in addition to occupational factors encompassing silica exposure, duration of employment, and type of work setting.

CONCLUSION

The findings of this scoping review highlight the research gaps in the reviewed literature, including the dearth of longitudinal studies focusing on the directionality of the two comorbidities (TB and silicosis) that lead to STB, lack of gender considerations in research on this topic, and an absence of articles on vulnerable populations including children. The findings of this review may help guide future research and inform occupational health and safety policies addressing STB outcomes among miners.

A comprehensive retrospect on the current perspectives and future prospects of pneumoconiosis

Pneumoconiosis is a widespread occupational pulmonary disease caused by inhalation and retention of dust particles in the lungs, is characterized by chronic pulmonary inflammation and progressive fibrosis, potentially leading to respiratory and/or heart failure. Workers exposed to dust, such as coal miners, foundry workers, and construction workers, are at risk of pneumoconiosis. This review synthesizes the international and national classifications, epidemiological characteristics, strategies for prevention, clinical manifestations, diagnosis, pathogenesis, and treatment of pneumoconiosis. Current research on the pathogenesis of pneumoconiosis focuses on the influence of autophagy, apoptosis, and pyroptosis on the progression of the disease. In addition, factors such as lipopolysaccharide and nicotine have been found to play crucial roles in the development of pneumoconiosis. This review provides a comprehensive summary of the most fundamental achievements in the treatment of pneumoconiosis with the purpose of indicating the future direction of its treatment and control. New technologies of integrative omics, artificial intelligence, systemic administration of mesenchymal stromal cells have proved useful in solving the conundrum of pneumoconiosis. These directional studies will provide novel therapeutic targets for the treatment of pneumoconiosis.

Coal Worker's Pneumoconiosis Mimicking Lung Cancer in a 75-Year-Old Woman With a History of Breast Cancer: A Clinical Case Report

Pneumoconiosis, caused by inhaling mineral dust, remains a significant occupational disease, despite a declining incidence. Coal workers' pneumoconiosis (CWP), a common subtype, varies in presentation from simple to complicated forms. Differential diagnosis is crucial, especially when CWP manifests as lung masses mimicking malignancy. We present a case of CWP in a 75-year-old female with a history of breast cancer, initially suspected of lung cancer due to an incidental mass on chest radiography. Clinical examination, laboratory tests, chest tomography, and biopsy were conducted. The patient, with a history of biomass fuel exposure, presented with a left upper lung mass, initially thought to be lung cancer. Biopsy-induced hemopneumothorax led to intensive care admission. Histopathology confirmed CWP and conservative management resulted in recovery. Imaging revealed a solid mass in the left upper lung with lymphadenopathy. Histopathology showed carbon-laden macrophages and anthracosis, consistent with CWP. Imaging modalities, including MRI and FDG-PET/CT, aid in differentiating CWP from cancer. CWP, mimicking lung cancer, underscores the importance of accurate diagnosis. Imaging features, including nodules with calcifications, guide diagnosis. MRI and FDG-PET/CT offer valuable insights, albeit with limitations, emphasizing the need for judicious use based on clinical suspicion.

Risk of mycobacterial infections in a cohort of silicosis patients with autoimmune rheumatic diseases

OBJECTIVE

To evaluate the incidence rates of mycobacterial infections in silicosis patients with systemic autoimmune rheumatic disease (ARD).

METHODS

This was a retrospective cohort of silicosis patients between January of 1999 and December of 2023. We compared the incidence of tuberculosis and nontuberculous mycobacterial disease (NTM) in patients with silicosis with and without ARD. We also compared the tuberculosis incidence in the overall cohort with general Brazilian population estimates.

RESULTS

The study comprised 369 silicosis patients, of whom 35 (9.5%) had ARD. Having ARD did not affect the cumulative incidence of mycobacterial diseases. The risk of tuberculosis was higher in the cohort when compared with that in the adult Brazilian male population (age-adjusted incidence rate ratio = 20.46; 95% CI 14.89-28.13).

CONCLUSIONS

In this cohort of patients with silicosis, ARD was not associated with the incidence of mycobacterial diseases.

Silico-tuberculosis: An updated review

Silico-Tuberculosis (silico-TB) is a severe combination of tuberculosis and silicosis, caused by occupational exposure to fine crystalline silica dust, which has become a global health concern. This comprehensive review compiles the updated knowledge regarding pathophysiology, clinical manifestations, important diagnostic techniques, treatment aspects, and challenges in understanding silico-TB. The review compiles the disease's history and epidemiology, highlighting a lack of data owing to poor monitoring and healthcare particularly in low- and middle-income countries like India. Further weak safety regulations, lack of preventative measures, and inadequate education increase the rates of silico-TB. The pathophysiology shows how silica particles impair the immune system and stimulate Th2 cells and M2 macrophages, which exacerbate TB, while inhibiting Th1 cells and M1 macrophages, which fight against the disease. Subsequently, it can be difficult to distinguish current TB from pre-existing silicosis. In cases where sputum and X-ray results are negative, chest CT scans may be helpful since radiographic screening identifies TB earlier than sputum assessment. Isoniazid, rifampicin, or both minimize the risk of active tuberculosis in people with silicosis. Consistent anti-tuberculosis drug therapy is recommended for 8-9 months to stop recurrence. The assessment recommends integrating silicosis and TB control initiatives to fight this combined health issue.

Computed Tomography of Contemporary Occupational Lung Disease: A Pictorial Review

Occupational lung disease remains one of the most common work-related illnesses and accounts for most deaths from occupational illness. Occupational lung diseases often have delayed manifestation over decades and nonspecific clinical presentations, making it challenging for clinicians to promptly identify the disease and implement preventive measures. Radiologists play a crucial role in identifying and diagnosing occupational lung diseases, allowing for removal of the exposure and early medical intervention. In this review, we share our clinical and radiologic approach to diagnosing occupational lung disease and its subtypes. A collection of sample cases of occupational lung diseases commonly encountered in the modern era at a large Canadian university hospital is included to facilitate understanding. This review will provide radiologists with valuable insights into recognizing and diagnosing occupational lung diseases.

The role of pathologists in the diagnosis of occupational lung diseases: an expert opinion of the European Society of Pathology Pulmonary Pathology Working Group

Occupational lung/thoracic diseases are a major global public health issue. They comprise a diverse spectrum of health conditions with complex pathology, most of which arise following chronic heavy workplace exposures to various mineral dusts, metal fumes, or following inhaled organic particulate reactions. Many occupational lung diseases could become irreversible; thus accurate diagnosis is mandatory to minimize dust exposure and consequently reduce damage to the respiratory system. Lung biopsy is usually required when exposure history is inconsistent with imaging, in case of unusual or new exposures, in case of unexpected malignancy, and in cases in which there are claims for personal injury and legal compensation. In this paper, we provide an overview of the most frequent occupational lung diseases with a focus on pathological diagnosis. This is a paper that summarizes the expert opinion from a group of European pathologists, together with contributions from other specialists who are crucial for the diagnosis and management of these diseases. Indeed, tight collaboration of all specialists involved in the workup is mandatory as many occupational lung diseases are misdiagnosed or go unrecognized. This document provides a guide for pathologists in practice to facilitate the accurate diagnosis of occupational lung disease. The review article reports relevant topics discussed during an educational course held by expert pathologists, active members of the Pulmonary Pathology Working Group of the European Society of Pathology. The course was endorsed by the University of Padova as a "winter school" (selected project in the call for "Shaping a World-class University" 2022).

[Differential diagnosis of cystic and nodular lung diseases]

BACKGROUND

Cystic and nodular lung diseases encompass a broad spectrum of diseases with different etiologies and clinicoradiological presentations. Their differentiation is crucial for patient management but can be complex due to diseases with features of both categories and overlapping radiological patterns.

OBJECTIVE

This study aims to describe the imaging features of cystic and nodular lung diseases in high-resolution computed tomography (CT) in detail-primarily based on their etiology-in order to allow a more accurate differential diagnosis of these diseases.

MATERIALS AND METHODS

A narrative review based on current literature on the topic was conducted from a clinicoradiological perspective.

RESULTS

This paper systematically categorizes the differential diagnosis of cystic and nodular lung disease and provides insights into their radiological patterns and etiologies. It highlights the role of CT in the diagnosis of these diseases and emphasizes the importance of multidisciplinary panels combining expertise from radiology, pulmonology, rheumatology, and pathology.

CONCLUSION

Reliable differential diagnosis of cystic and nodular lung diseases, particularly based on their radiological features alone, remains difficult due to their overlapping and dynamic nature. Multidisciplinary boards should be the clinical standard for accurate work-up of these diseases, as they combine the medical history, symptoms, radiological findings, and, if necessary, histopathological examinations, thus providing a more robust framework for diagnosis and management.

[Occupational interstitial lung diseases]

A variety of workplace exposures (organic or inorganic dusts as well as gases, fumes, or vapors) can cause diffuse interstitial lung disease. The latency period until onset of the disease can exceed 30 years. The disease course varies greatly and depends on the quantity of the inhaled substance and its fibrogenic effect. Pulmonary high-resolution computed tomography (HRCT) patterns do not differ significantly from those of interstitial lung diseases (ILD) of other etiologies. Therefore, without knowledge of the occupational history, work-related ILDs are often classified as idiopathic. In addition, there is increasing evidence in the recent literature that high exposure to silica dust can trigger autoimmune diseases (also involving the lungs). For this reason, a qualified occupational history is now an indispensable part of the interdisciplinary diagnosis of ILDs.

The Diagnostic Value of Endobronchial Ultrasound-Guided Fine Needle Aspiration (EBUS-FNA) in Diagnosing FDG-PET-Avid Lymph Nodes in Extrapulmonary Malignancies

Background and objective The accurate diagnosis of extrapulmonary malignancies with mediastinal lymphadenopathy is crucial for effective patient management. Endobronchial ultrasound-guided fine-needle aspiration (EBUS-FNA) has emerged as a valuable tool in assessing fluorodeoxyglucose (FDG)-positron emission tomography (PET)-avid lymph nodes (LNs). In this study, we aimed to evaluate the diagnostic value of EBUS-FNA in patients with mediastinal lymphadenopathy in extrapulmonary malignancies and compare its efficacy with PET-CT.  Methodology This retrospective, cross-sectional study was conducted at Shaukat Khanum Memorial Cancer Hospital and Research Center, Lahore, from February 2018 to February 2023. It included patients with extrapulmonary malignancies with mediastinal lymphadenopathy displaying abnormal PET-CT uptake, with LN diameters ≥5 mm, excluding lung cancer cases. Data on demographics, malignancy type, LN involvement, PET-CT findings, and EBUS-FNA histopathology were collected. EBUS-FNA procedures involved a 22-gauge needle, and samples were analyzed cytologically and histologically. SPSS Statistics version 20 (IBM Corp., Armonk, NY) was used to perform the statistical analysis. Results The study analyzed a total of 216 patients. Males comprised 56.3% of the cohort, and females 43.7%. The most common malignancy was lymphoma (33.0%), followed by breast cancer (12.6%). EBUS-FNA exhibited a sensitivity of 90.9% compared to PET-CT's sensitivity of 72.7%. Lymph node morphology on EBUS showed low echogenicity and irregular borders in malignant cases. Subcarinal and right hilar were the most frequently sampled lymph nodes. The study found significant differences in lymph node characteristics between non-malignant and malignant groups, with EBUS-FNA effectively identifying malignancies.  Conclusions EBUS-FNA demonstrates high sensitivity and diagnostic utility in identifying malignant lymph nodes in patients with extrapulmonary malignancies. Its effectiveness in detecting true positive cases highlights its importance as a complementary diagnostic tool to PET-CT in oncological diagnostics.

Silico-Tuberculosis Mimicking Malignancy

Silico-tuberculosis is the combination of silicosis and tuberculosis (TB). Symptoms of TB such as dyspnea, cough, and hemoptysis may precede the diagnosis of an endo-bronchial mass lesion on chest imaging. Among workers who were exposed to silica, TB was more common, and experiments indicated that silica inhibits alveolar macrophage activity and severe exposure induces apoptosis. Endobronchial neoplasms, which are tumors primarily affecting the bronchial lumen, are uncommon and may show up in a wide variety of different ways pathologically. Cough, chest discomfort, wheezing, hemoptysis, recurrent pneumonia, and weight loss are common complaints from people with endobronchial tumors. The requirement for additional bronchoscopy and imaging examination is raised when symptoms such as hemoptysis and obstructive pneumonia are present. Endobronchial silicosis lesions are uncommon and develop as a result of broncho lithiasis, the endoluminal erosion of peri bronchial adenopathy, or local bronchial wall silica-induced fibrosis. Endobronchial TB can present in a varied manner, diagnosis is often challenging as there is no specific radiological feature, and sputum acid-fast bacilli several times come out negative. However, a bronchoscopy with or without biopsy is a useful investigation in these cases. The following case is a rare manifestation of endobronchial TB as it mimicked malignancy, describing the difficulties in diagnosis and treating a patient who had both silicosis and endobronchial TB.

Potential of digital chest radiography-based deep learning in screening and diagnosing pneumoconiosis: An observational study

The diagnosis of pneumoconiosis is complex and subjective, leading to inevitable variability in readings. This is especially true for inexperienced doctors. To improve accuracy, a computer-assisted diagnosis system is used for more effective pneumoconiosis diagnoses. Three models (Resnet50, Resnet101, and DenseNet) were used for pneumoconiosis classification based on 1250 chest X-ray images. Three experienced and highly qualified physicians read the collected digital radiography images and classified them from category 0 to category III in a double-blinded manner. The results of the 3 physicians in agreement were considered the relative gold standards. Subsequently, 3 models were used to train and test these images and their performance was evaluated using multi-class classification metrics. We used kappa values and accuracy to evaluate the consistency and reliability of the optimal model with clinical typing. The results showed that ResNet101 was the optimal model among the 3 convolutional neural networks. The AUC of ResNet101 was 1.0, 0.9, 0.89, and 0.94 for detecting pneumoconiosis categories 0, I, II, and III, respectively. The micro-average and macro-average mean AUC values were 0.93 and 0.94, respectively. The accuracy and Kappa values of ResNet101 were 0.72 and 0.7111 for quadruple classification and 0.98 and 0.955 for dichotomous classification, respectively, compared with the relative standard classification of the clinic. This study develops a deep learning based model for screening and staging of pneumoconiosis is using chest radiographs. The ResNet101 model performed relatively better in classifying pneumoconiosis than radiologists. The dichotomous classification displayed outstanding performance, thereby indicating the feasibility of deep learning techniques in pneumoconiosis screening.

Incidence, mortality, and disability-adjusted life years due to silicosis worldwide, 1990-2019: evidence from the global burden of disease study 2019

Silicosis is an occupational lung disease because of exposure to silica dust in the workplace. Evidence on the spatiotemporal change of silicosis burden worldwide remains limited. This study utilized data extracted from the Global Burden of Disease Study 2019 to examine the numbers and age-standardized rates of incidence (ASIR), mortality (ASMR), and disability-adjusted life years (DALYs) caused by silicosis between 1990 and 2019. Average annual percentage changes (AAPCs) were calculated to evaluate the temporal trends of age-standardized indicators by sex, region, and socio-demographic index (SDI) since 1990. Results indicated an increase in new silicosis cases globally, rising by 64.61% from 84,426 in 1990 to 138,971 in 2019, with a sustained high number of DALYs attributed to this disease. Although the global age-standardized rates of incidence, mortality, and DALYs of silicosis have decreased since 1990, the number of new cases has increased in 168 countries and territories, and the ASIR of silicosis has also risen in 118 countries and territories, primarily in developing countries. Since 1990, the burden of silicosis among the elderly has significantly increased. Countries with higher SDI experienced a more rapid decline in the silicosis burden. Silicosis remains a public health problem that requires significant attention. Programs for prevention and elimination of this public health issue need to be established in more countries and territories. Protecting young workers from silica dust exposure is crucial to prevent the onset of silicosis in their later years and to reduce the disease burden among older workers.

Elevated Levels of the Cancer Marker Neuron-Specific Enolase in a Patient With Coexisting Silicosis and Sarcoidosis

In a periodical medical checkup, a 39-year-old Mongolian underground miner was diagnosed with silicosis based on chest radiography, computed tomography (CT), and work history. Chest radiography showed diffuse bilateral rounded nodules in both lung fields, with upper lobe dominance and large opacities in the right upper zone. Chest CT presented conglomerated massive changes in the right upper lobe and the coalescence of small nodules in the left upper lung. In the blood test, serum levels of the lung cancer marker neuron-specific enolase (NSE) were elevated (24.58 ng/mL). Carcinoembryonic antigen (CEA) and cytokeratin 19 fragment (CYFRA 21-1) levels were within the reference range. Subsequent to the suspicion of a tumour in the right upper lobe, a right upper lobectomy was performed. The histopathological examination of the lung specimen revealed the coalescence of numerous silica nodules, accompanied by indications of associated sarcoidosis. The histological features suggested the presence of two concurrent pathological processes: silicosis and sarcoidosis. This case demonstrated the combination of three clinical conditions diagnosed in one patient, including complicated silicosis associated with sarcoidosis and elevated serum NSE levels. This case report may serve as a foundation for future investigations exploring the potential of NSE as a marker for silicosis.

Silico-tuberculosis amidst COVID-19 pandemic: global scenario and Indian perspective

Inhalation of crystalline silica-rich dust particles can result in the deadly occupational lung disorder called silicosis. The risk of contracting tuberculosis (TB) and the potential for lung cancer increase due to silicosis. This review article aims to bring to light the state of silicosis and TB scenario in the world and India for evaluating hurdles in the present and future to achieve the elimination road map and assess these conditions in the backdrop of the COVID-19 pandemic. A patient with silicosis has a 2.8-2.9 times higher risk of developing pulmonary TB and 3.7 times that of extrapulmonary TB. Incidences of missed cases when TB was misdiagnosed with silicosis due to indifferent clinical manifestations of the two in the initial stages are not uncommon. The duration of silica exposure and silicosis severity are directly related to the propensity to develop TB. As per a study, an average gap of 7.6 years has been noticed in a South African population for silico-tuberculosis to develop post-silicosis. In a study done on mine workers at Jodhpur, Rajasthan, it was seen that there is no definitive relation between patients with silicosis and the possibility of having COVID-19. There is a significant need to integrate the Silicosis control program with the TB elimination program for the government. A few steps can include assessing the workplaces, periodic monitoring of the workers' health, active case surveillance, identification of hotspots, and introducing reforms to curb the spread of dust and particulate matter from industrialised areas be taken in this regard.

Cross-sectional imaging review of common to uncommon lung cancer mimickers in a tertiary care oncology center

Lung cancer is the most diagnosed cancer worldwide. Many non-malignant pulmonary lesions, such as tuberculosis, fungal infection, organizing pneumonia, inflammatory myofibroblastic tumor, and IgG4 disease, can mimic lung cancer due to their overlapping morphological appearance on imaging. These benign entities with minor differentiating imaging clues may go unnoticed in a high-volume cancer institution, leading to over-investigation that may result in repeated biopsies, pointless wedge resections, and related morbidities. However, with a thorough medical history, laboratory diagnostic work-up, and careful analysis of imaging findings, one can occasionally restrict the range of possible diagnoses or arrive at a definitive conclusion. When imaging features overlap, image-guided lung sampling is crucial since histopathological analysis is the gold standard.

Lung adenocarcinoma presenting with intrapulmonary metastases through air spaces concomitant with silicosis: a case report and literature review

Herein, we reported a rare case of bilateral intrapulmonary metastases spread through air spaces (STAS) and silicosis to advance understanding and knowledge of this disease. A middle-aged man was diagnosed with a left upper lung nodule with bilateral silicosis by preoperative imaging. Local pleural indentation and extensive metastases spread in the visceral pleura were observed during the operation. Pathological examination showed multiple metastases of lung adenocarcinoma, and STAS positive. Genetic testing indicated EGFR mutation, and ektinib was administered. STAS can promote lung cancer, leading to multiple pulmonary metastases, and silicosis can contribute to the carcinogenesis of lung cancer. This case provided valuable clinical lessons. More studies are warranted to elucidate the role and underlying mechanism of silicosis and STAS in the development of lung cancer. More accurate imaging methods and radiographic criteria should be formulated for different diffuse nodules and STAS grades, and the exploration of optimal therapeutic regimens to treat these concomitant patients is urgently needed to improve diagnostic rates and formulate more optimal therapies.

A review of pulmonary neutrophilia and insights into the key role of neutrophils in particle-induced pathogenesis in the lung from animal studies of lunar dusts and other poorly soluble dust particles

The mechanisms of particle-induced pathogenesis in the lung remain poorly understood. Neutrophilic inflammation and oxidative stress in the lung are hallmarks of toxicity. Some investigators have postulated that oxidative stress from particle surface reactive oxygen species (psROS) on the dust produces the toxicopathology in the lungs of dust-exposed animals. This postulate was tested concurrently with the studies to elucidate the toxicity of lunar dust (LD), which is believed to contain psROS due to high-speed micrometeoroid bombardment that fractured and pulverized lunar surface regolith. Results from studies of rats intratracheally instilled (ITI) with three LDs (prepared from an Apollo-14 lunar regolith), which differed 14-fold in levels of psROS, and two toxicity reference dusts (TiO2 and quartz) indicated that psROS had no significant contribution to the dusts' toxicity in the lung. Reported here are results of further investigations by the LD toxicity study team on the toxicological role of oxidants in alveolar neutrophils that were harvested from rats in the 5-dust ITI study and from rats that were exposed to airborne LD for 4 weeks. The oxidants per neutrophils and all neutrophils increased with dose, exposure time and dust's cytotoxicity. The results suggest that alveolar neutrophils play a critical role in particle-induced injury and toxicity in the lung of dust-exposed animals. Based on these results, we propose an adverse outcome pathway (AOP) for particle-associated lung disease that centers on the crucial role of alveolar neutrophil-derived oxidant species. A critical review of the toxicology literature on particle exposure and lung disease further supports a neutrophil-centric mechanism in the pathogenesis of lung disease and may explain previously reported animal species differences in responses to poorly soluble particles. Key findings from the toxicology literature indicate that (1) after exposures to the same dust at the same amount, rats have more alveolar neutrophils than hamsters; hamsters clear more particles from their lungs, consequently contributing to fewer neutrophils and less severe lung lesions; (2) rats exposed to nano-sized TiO2 have more neutrophils and more severe lesions in their lungs than rats exposed to the same mass-concentration of micron-sized TiO2; nano-sized dust has a greater number of particles and a larger total particle-cell contact surface area than the same mass of micron-sized dust, which triggers more alveolar epithelial cells (AECs) to synthesize and release more cytokines that recruit a greater number of neutrophils leading to more severe lesions. Thus, we postulate that, during chronic dust exposure, particle-inflicted AECs persistently release cytokines, which recruit neutrophils and activate them to produce oxidants resulting in a prolonged continuous source of endogenous oxidative stress that leads to lung toxicity. This neutrophil-driven lung pathogenesis explains why dust exposure induces more severe lesions in rats than hamsters; why, on a mass-dose basis, nano-sized dusts are more toxic than the micron-sized dusts; why lung lesions progress with time; and why dose-response curves of particle toxicity exhibit a hockey stick like shape with a threshold. The neutrophil centric AOP for particle-induced lung disease has implications for risk assessment of human exposures to dust particles and environmental particulate matter.

Occupational Lung Diseases: Spectrum of Common Imaging Manifestations

Occupational lung diseases (OLD) are a group of preventable conditions caused by noxious inhalation exposure in the workplace. Workers in various industries are at a higher risk of developing OLD. Despite regulations contributing to a decreased incidence, OLD remain among the most frequently diagnosed work-related conditions, contributing to significant morbidity and mortality. A multidisciplinary discussion (MDD) is necessary for a timely diagnosis. Imaging, particularly computed tomography, plays a central role in diagnosing OLD and excluding other inhalational lung diseases. OLD can be broadly classified into fibrotic and non-fibrotic forms. Imaging reflects variable degrees of inflammation and fibrosis involving the airways, parenchyma, and pleura. Common manifestations include classical pneumoconioses, chronic granulomatous diseases (CGD), and small and large airway diseases. Imaging is influenced by the type of inciting exposure. The findings of airway disease may be subtle or solely uncovered upon expiration. High-resolution chest CT, including expiratory-phase imaging, should be performed in all patients with suspected OLD. Radiologists should familiarize themselves with these imaging features to improve diagnostic accuracy.

Tips and Tricks in Thoracic Radiology for Beginners: A Findings-Based Approach

This review has the purpose of illustrating schematically and comprehensively the key concepts for the beginner who approaches chest radiology for the first time. The approach to thoracic imaging may be challenging for the beginner due to the wide spectrum of diseases, their overlap, and the complexity of radiological findings. The first step consists of the proper assessment of the basic imaging findings. This review is divided into three main districts (mediastinum, pleura, focal and diffuse diseases of the lung parenchyma): the main findings will be discussed in a clinical scenario. Radiological tips and tricks, and relative clinical background, will be provided to orient the beginner toward the differential diagnoses of the main thoracic diseases.

Pathology and Mineralogy of the Pneumoconioses

Pneumoconioses represent the spectrum of lung diseases caused by inhalation of respirable particulate matter small enough (typically <5-µm diameter) to reach the terminal airways and alveoli. Pneumoconioses primarily occur in occupational settings where workers perform demanding and skilled manual labor including mining, construction, stone fabrication, farming, plumbing, electronics manufacturing, shipyards, and more. Most pneumoconioses develop after decades of exposure, though shorter latencies can occur from more intense particulate matter exposures. In this review, we summarize the industrial exposures, pathologic findings, and mineralogic features of various well-characterized pneumoconioses including silicosis, silicatosis, mixed-dust pneumoconiosis, coal workers' pneumoconiosis, asbestosis, chronic beryllium disease, aluminosis, hard metal pneumoconiosis, and some less severe pneumoconioses. We also review a general framework for the diagnostic work-up of pneumoconioses for pulmonologists including obtaining a detailed occupational and environmental exposure history. Many pneumoconioses are irreversible and develop due to excessive cumulative respirable dust inhalation. Accurate diagnosis permits interventions to minimize ongoing fibrogenic dust exposure. A consistent occupational exposure history coupled with typical chest imaging findings is usually sufficient to make a clinical diagnosis without the need for tissue sampling. Lung biopsy may be required when exposure history, imaging, and testing are inconsistent, there are unusual or new exposures, or there is a need to obtain tissue for another indication such as suspected malignancy. Close collaboration and information-sharing with the pathologist prior to biopsy is of great importance for diagnosis, as many occupational lung diseases are missed due to insufficient communication. The pathologist has a broad range of analytic techniques including bright-field microscopy, polarized light microscopy, and special histologic stains that may confirm the diagnosis. Advanced techniques for particle characterization such as scanning electron microscopy/energy dispersive spectroscopy may be available in some centers.

Differential diagnosis of pulmonary sarcoidosis: a review

Diagnosing pulmonary sarcoidosis raises challenges due to both the absence of a specific diagnostic criterion and the varied presentations capable of mimicking many other conditions. The aim of this review is to help non-sarcoidosis experts establish optimal differential-diagnosis strategies tailored to each situation. Alternative granulomatous diseases that must be ruled out include infections (notably tuberculosis, nontuberculous mycobacterial infections, and histoplasmosis), chronic beryllium disease, hypersensitivity pneumonitis, granulomatous talcosis, drug-induced granulomatosis (notably due to TNF-a antagonists, immune checkpoint inhibitors, targeted therapies, and interferons), immune deficiencies, genetic disorders (Blau syndrome), Crohn's disease, granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, and malignancy-associated granulomatosis. Ruling out lymphoproliferative disorders may also be very challenging before obtaining typical biopsy specimen. The first step is an assessment of epidemiological factors, notably the incidence of sarcoidosis and of alternative diagnoses; exposure to risk factors (e.g., infectious, occupational, and environmental agents); and exposure to drugs taken for therapeutic or recreational purposes. The clinical history, physical examination and, above all, chest computed tomography indicate which differential diagnoses are most likely, thereby guiding the choice of subsequent investigations (e.g., microbiological investigations, lymphocyte proliferation tests with metals, autoantibody assays, and genetic tests). The goal is to rule out all diagnoses other than sarcoidosis that are consistent with the clinical situation. Chest computed tomography findings, from common to rare and from typical to atypical, are described for sarcoidosis and the alternatives. The pathology of granulomas and associated lesions is discussed and diagnostically helpful stains specified. In some patients, the definite diagnosis may require the continuous gathering of information during follow-up. Diseases that often closely mimic sarcoidosis include chronic beryllium disease and drug-induced granulomatosis. Tuberculosis rarely resembles sarcoidosis but is a leading differential diagnosis in regions of high tuberculosis endemicity.

Imaging diagnosis of pneumoconiosis with predominant nodular pattern: HRCT and pathologic findings

The radiological patterns of known pneumoconiosis have been changing in recent years. The basic pathology in pneumoconiosis is the presence of dust macules, mixed dust fibrosis, nodules, diffuse interstitial fibrosis, and progressive massive fibrosis. These pathologic changes can coexist in dust-exposed workers. High resolution CT reflects pathological findings in pneumoconiosis and is useful for the diagnosis. Pneumoconiosis such as silicosis, coal workers' pneumoconiosis, graphite pneumoconiosis, and welder's pneumoconiosis, has predominant nodular HRCT pattern. Diffuse interstitial pulmonary fibrosis is sometimes found in the lungs of this pneumoconiosis. In the early stages of metal lung, such as aluminosis and hard metal lung, centrilobular nodules are predominant findings, and in the advanced stages, reticular opacities are predominant findings. The clinician must understand the spectrum of expected imaging patterns related to known dust exposures and novel exposures. In this article, HRCT and pathologic findings of pneumoconiosis with predominant nodular opacities are shown.

Suspicious lung lesions for malignancy: the lesion-to-spinal cord signal intensity ratio in T2WI and DWI–MRI versus PET/CT; a prospective pathologic correlated study with accuracy and ROC analyses

Background

The multi-detector computed tomography (MDCT) and tissue biopsy are the gold standards for the evaluation of lung malignancies. However, there is a wide range of pulmonary indeterminate lesions that could mimic lung cancer. Furthermore, the diagnosis of malignancy could be challenging if the lesion is small and early presenting by a part-solid or ground-glass nodule or if surrounded by parenchymal lung reaction with consolidation and atelectasis. The previous literature focused on the role of diffusion-weighted image–magnetic resonance imaging (DWI) and the apparent diffusion coefficient (ADC) mapping in the evaluation of lung malignancy. A novel quantitative T2 assessment is provided and tested in this study. Aim of the work: To evaluate the accuracy of specific non-invasive quantitative magnetic resonance imaging (MRI) parameters in the characterization of suspicious lung lesions and the discrimination between the malignant and benign nature. They included the lesion-to-spinal cord signal intensity ratio in T2-WI and DWI as well as the mean and minimum apparent diffusion coefficient (ADC) values. This is performed using a prospective pathologic correlated study with receiver-operating characteristics (ROC) analysis and comparison with positron emission tomography (PET-CT) accuracy results.

Results

This study was prospectively performed during the period between June/2021 and June/2022. It was conducted on 43 suspicious lung lesions detected by MDCT. MRI and PET/CT examinations were performed for all patients, and the results were compared to the final diagnosis obtained after biopsy and pathological assessment, using the statistical tests of significance and P-value. Cutoff values were automatically calculated, and then, accuracy tests and ROC analyses were performed. Five expert radiologists and a single consulting pulmonologist participated in this study. The inter-rater reliability ranges between good and excellent with the intra-class correlation coefficient (ICC) ranging between 0.85 and 0.94. In T2-WI: The lesion-to-spinal cord signal intensity ratio was higher in the malignant group (1.35 ± 0.29) than in the benign group (0.88 ± 0.40), (P < 0.001). At the estimated cutoff value (> 1), the sensitivity was 96.43%, the specificity was 80.00%, and AUC = 0.86. In b500-DWI: The lesion-to-spinal cord signal intensity ratio was higher in the malignant group (0.70–1.35) than in the benign group (0.20–0.70) (P < 0.001). At the estimated cutoff value (> 0.7), the sensitivity was 71.43%, the specificity was 86.67%, and AUC = 0.86. The mean and minimum ADC values were lower in the malignant group (0.6–1.3 and 0.3–1.1 × 10–3 mm2/s) than the benign group (1–1.6 and 0.7–1.4 × 10–3 mm2/s), (P < 0.01 and < 0.001, respectively). At their estimated cutoff values (≤ 1.2 and ≤ 0.9 × 10–3 mm2/s, respectively), the sensitivity was (71.4 and 85.7%), specificity was (83.3 and 66.7%), respectively, and AUC = 0.77 for both. PET/CT had 96.4% sensitivity, 92.3% specificity, and AUC = 0.94.

Conclusions

PET-CT remains the most specific and sensitive tool for the differentiation between benign and malignant lesions. The lesion-to-cord signal intensity ratios in T2WI and DWI-MRI and to a minor extent the mean and minimum ADC values are also considered good parameters for this differentiation based on their accurate statistical results, particularly if PET/CT was not available or feasible. The study added to the previous literature a novel quantitative T2WI assessment which proved a high sensitivity equal to PET/CT with a lower but a good specificity. The availability, expertise, time factor, and patients' tolerance remain challenging factors for MRI.

How I treat refractory/relapsed diffuse large B-cell lymphomas with CD19-directed chimeric antigen receptor T cells

Chimeric antigen receptor (CAR) T cells targeting CD19 represent a promising salvage immunotherapy for relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL), offering ~40% of long-term responses. In everyday clinical practice, haematologists involved in CAR T cell treatment of patients with R/R DLBCL have to deal with diagnostically complex cases and difficult therapeutic choices. The availability of novel immunotherapeutic agents for R/R DLBCL and recent advances in understanding CAR T-cell failure mechanisms demand a rational approach to identify the best choice for bridging therapy and managing post-CAR T-cell therapy relapses. Moreover, positron emission tomography/computerised tomography may result in false-positive interpretation, highlighting the importance of post-treatment biopsy. In this review, we discuss all above issues, presenting four instructive cases, with the aim to provide criteria and new perspectives for CAR T-cell treatment of DLBCL.

The temporal characteristics of the disruption of gut microbiota, serum metabolome, and cytokines by silica exposure in wistar rats

Silicosis is one of the most frequent, rapidly developing, and lethal types of pneumoconiosis. However, our understanding of the underlying mechanisms of its pathogenesis and progress remains unclear. We investigated the fundamental processes of silicosis incidence and progression using a combination of lung function testing, histopathology, 16 S rRNA, untargeted metabolomics, and cytokine chips at different exposure times (4 or 8 weeks). The results show that silica exposure damages lung tissue reduces lung function, and increases with time. Cytokines with time-specific properties were found in lung lavage fluid: IFN-γ (4 weeks; P＜0.05), TNF-α, M-CSF, GM-CSF (8 weeks; P＜0.01). In addition, silica exposure for different periods interferes to varying degrees with the metabolism of lipids. The composition of the intestinal microbiota changed with increasing exposure time and there were time-specific: Allobaculum, Turicibacter、Jeotgalicoccu、Coprococcus 1 (4 weeks; P＜0.05), Ruminococcaceae NK4A214 group、Ruminiclostridium 5 (8 weeks; P＜0.05). We found strong associations between cytokines, gut microbiota changes, and metabolic disturbances at different exposure times. These results suggest that time-specific changes in crosstalk among cytokines, the gut microbiota, and metabolites may be a potential mechanism for silica-induced lung injury.

Occupational Interstitial Lung Diseases

Occupational exposures are directly causal or partially contributory to the development of interstitial lung diseases. A detailed occupational history, relevant high-resolution computed tomography findings, and where relevant additional histopathology, are required to make a diagnosis. Treatment options are limited, and further exposure avoidance is likely to reduce disease progression.

An unusual case of interstitial lung disease: Revisiting peribronchiolar metaplasia interstitial lung disease (PBM-ILD)

Peribronchiolar metaplasia (PBM) is a histological finding of uncertain significance commonly seen in interstitial lung disease (ILD). PBM is thought to be secondary to small airway injury from insults such as tobacco smoke and other environmental exposures. The term PBM-ILD has been proposed for patients with ILD where PBM is the major histologic finding, however a lack of radiographic changes supportive of ILD in previously reported cases has limited recognition of the diagnosis. We present a rare case of welding-associated ILD with clinical, radiographic, and histologic evidence consistent with the proposed definition of PBM-ILD. We outline an approach to its consideration as a diagnosis based on our experience through multidisciplinary discussion.

Co-occurrence of pneumoconiosis with COPD, pneumonia and lung cancer

BACKGROUND

Pneumoconiosis is a well-documented occupational disease that is linked to conditions such as chronic obstructive pulmonary disease (COPD), pneumonia and congestive heart failure. Pneumoconiosis prevalence has decreased in the United States, but it remains implicated in tens of thousands of deaths worldwide per year.

AIMS

To provide a recent update on associations of pneumoconiosis and smoking status with various pulmonary diseases in the United States.

METHODS

The CDC's National Vital Statistics System was analysed on the entity axis using ICD-10 codes for pulmonary disease and potential lung injury with a cohort of those aged 15 and older during the years 2010-2019. The cases of evaluated diseases were scaled to rates per 100 000 and compared through analysis of variance.

RESULTS

Pneumoconiosis and smoking history were each associated with an increased rate of COPD, but combined, were associated with an even higher rate of COPD than either factor alone. Smoking history was associated with an increased rate of lung cancer, but pneumoconiosis status was only linked to increased lung cancer prevalence in non-smokers. Both pneumoconiosis and smoking were associated with an increased rate of pneumonia, but combined, had no deviation from the pneumonia rate in those with pneumoconiosis alone. Finally, pneumoconiosis status was associated with decreased rates of non-lung cancers and sepsis.

CONCLUSIONS

Although pneumoconiosis has become less common in the United States through regulatory and industrial shifts, it is still a significant risk factor for co-occurring pulmonary diseases and will likely remain relevant as international demands for mining, construction and manufacturing change.

Inhalational lung diseases

The term inhalational lung disease comprises a group of entities that develop secondary to the active aspiration of particles. Most are occupational lung diseases. Inhalational lung diseases are classified as occupational diseases (pneumoconiosis, chemical pneumonitis), hypersensitivity pneumonitis, and electronic-cigarette-associated lung diseases. The radiologic findings often consist of nonspecific interstitial patterns that can be difficult to interpret. Therefore, radiologists' experience and multidisciplinary teamwork are key to ensure correct evaluation. The role of the radiologist is fundamental in preventive measures as well as in diagnosis and management, having an important impact on patients' overall health. It is crucial to take into account patients' possible exposure to particles both at work and at home.

Imaging of Occupational and Environmental Lung Disease

The respiratory tract is continuously exposed to and filters toxins from the home and work environments. Certain occupations and environmental exposures can cause unique injuries to the upper and lower respiratory system. Despite increasing federal regulations in the workplace, occupation-associated lung disease is still a major cause of lung disease and disability and continues to evolve with changes in industry, regulation, and new emerging exposures and toxins. Establishing a diagnosis can be difficult, often due to long latency between exposure and clinical disease, insufficient patient history, and nonspecific or varying imaging appearance. Identifying key imaging features of occupational lung disease along with a multidisciplinary approach can aid in accurate and timely diagnosis. In this review, we will discuss the importance of a comprehensive patient history, multidisciplinary approach to diagnosis, and key imaging features of occupation-related lung injuries. Radiographic and computed tomographic findings will be described and illustrated.

Two in one: Overlapping CT findings of COVID-19 and underlying lung diseases

Coronavirus disease 2019 (COVID-19) is associated with pneumonia and has various pulmonary manifestations on computed tomography (CT). Although COVID-19 pneumonia is usually seen as bilateral predominantly peripheral ground-glass opacities with or without consolidation, it can present with atypical radiological findings and resemble the imaging findings of other lung diseases. Diagnosis of COVID-19 pneumonia is much more challenging for both clinicians and radiologists in the presence of pre-existing lung disease. The imaging features of COVID-19 and underlying lung disease can overlap and obscure the findings of each other. Knowledge of the radiological findings of both diseases and possible complications, correct diagnosis, and multidisciplinary consensus play key roles in the appropriate management of diseases. In this pictorial review, the chest CT findings are presented of patients with underlying lung diseases and overlapping COVID-19 pneumonia and the various reasons for radiological lung abnormalities in these patients are discussed.

Progressive Massive Fibrosis Mimicking Lung Cancer: Two Case Reports with Potentially Useful CT Features for Differential Diagnosis

Progressive massive fibrosis (PMF) with atypical findings is often misdiagnosed as lung cancer. Atypical features of PMF have been described in some reports; however, these reports only introduced their cases with a short literature review. We report two cases of solitary PMFs with no underlying simple pneumoconiosis or rapid growth at atypical location that were mistaken for lung cancer. We also suggest the useful CT findings to aid in the differential diagnosis.

The burden of pneumoconiosis in China: an analysis from the Global Burden of Disease Study 2019

Background

Pneumoconiosis refers to a class of serious diseases threatening the health of workers exposed to coal or silicosis dust. However, the burden of pneumoconiosis is unavailable in China.

Methods

Incident cases, deaths, and disability-adjusted life years (DALYs) from pneumoconiosis and its subtypes in China were estimated from the Global Burden of Disease Study 2019 using a Bayesian meta-regression method. The trend of the burden from pneumoconiosis was analyzed using percentage change and annualized rate of change (ARC) during the period 1990–2019. The relationship between subnational socio-demographic index (SDI) and the ARC of age-standardised death rate was measured using Spearman’s Rank-Order Correlation.

Results

In 2019, there were 136.8 (95% uncertainty interval [UI] 113.7–162.5) thousand new cases, 10.2 (8.1–13.6) thousand deaths, and 608.7 (473.6–779.4) thousand DALYs from pneumoconiosis in China. Of the global burdens from pneumoconiosis, more than 60% were in China. Both the total number of new cases and DALYs from pneumoconiosis was keeping increasing from 1990 to 2019. In contrast, the age-standardised incidence, death, and DALY rates from pneumoconiosis and its subtypes, except for the age-standardised incidence rate of silicosis, and age-standardised death rate of asbestosis, experienced a significant decline during the same period. The subnational age-standardised death rates were higher in western China than in eastern China. Meanwhile, the subnational ARC of age-standardised death rates due to pneumoconiosis and its subtypes were significantly negatively correlated with SDI in 2019.

Conclusion

China suffers the largest health loss from pneumoconiosis in the world. Reducing the burden of pneumoconiosis is still an urgent task in China.

Computer-Aided Diagnosis of Coal Workers' Pneumoconiosis in Chest X-ray Radiographs Using Machine Learning: A Systematic Literature Review

Computer-aided diagnostic (CAD) systems can assist radiologists in detecting coal workers' pneumoconiosis (CWP) in their chest X-rays. Early diagnosis of the CWP can significantly improve workers' survival rate. The development of the CAD systems will reduce risk in the workplace and improve the quality of chest screening for CWP diseases. This systematic literature review (SLR) amis to categorise and summarise the feature extraction and detection approaches of computer-based analysis in CWP using chest X-ray radiographs (CXR). We conducted the SLR method through 11 databases that focus on science, engineering, medicine, health, and clinical studies. The proposed SLR identified and compared 40 articles from the last 5 decades, covering three main categories of computer-based CWP detection: classical handcrafted features-based image analysis, traditional machine learning, and deep learning-based methods. Limitations of this review and future improvement of the review are also discussed.

Gefitinib and fostamatinib target EGFR and SYK to attenuate silicosis: a multi-omics study with drug exploration

Silicosis is the most prevalent and fatal occupational disease with no effective therapeutics, and currently used drugs cannot reverse the disease progress. Worse still, there are still challenges to be addressed to fully decipher the intricated pathogenesis. Thus, specifying the essential mechanisms and targets in silicosis progression then exploring anti-silicosis pharmacuticals are desperately needed. In this work, multi-omics atlas was constructed to depict the pivotal abnormalities of silicosis and develop targeted agents. By utilizing an unbiased and time-resolved analysis of the transcriptome, proteome and phosphoproteome of a silicosis mouse model, we have verified the significant differences in transcript, protein, kinase activity and signaling pathway level during silicosis progression, in which the importance of essential biological processes such as macrophage activation, chemotaxis, immune cell recruitment and chronic inflammation were emphasized. Notably, the phosphorylation of EGFR (p-EGFR) and SYK (p-SYK) were identified as potential therapeutic targets in the progression of silicosis. To inhibit and validate these targets, we tested fostamatinib (targeting SYK) and Gefitinib (targeting EGFR), and both drugs effectively ameliorated pulmonary dysfunction and inhibited the progression of inflammation and fibrosis. Overall, our drug discovery with multi-omics approach provides novel and viable therapeutic strategies for the treatment of silicosis.

Volume-based tomography for the diagnosis of incipient silicosis in former gold miners

Objective

To evaluate silicosis diagnosed through CT, with integration of clinical-occupational data, in silica-exposed workers presenting chest X-rays within International Labor Organization (ILO) category 0.

Methods

Cross-sectional study with 339 former gold miners, with comparable exposures and X-rays classified as ILO subcategory 0/0 (n=285) and 0/1 (n=54) were submitted to volume-based CT. The findings were classified according to the International Classification of HRCT CT for Occupational and Environmental Respiratory Diseases.

Results

A profusion degree of round opacities (RO)>1 was found in 22.4% (76/339) of the CT exams. After integrating the CT findings with clinical and occupational data, silicosis was diagnosed as follows: 43/285 (15.1%) and 14/54 (25.9%) in workers whose X-rays had been classified as 0/0 and 0/1, respectively. There was an upward trend towards longer exposures, reaching 38.9% when working more than 10 years underground and classified as 0/1 (p=0019). Those with presence of RO whose final diagnosis was not silicosis were mainly cases of tuberculosis or ‘indeterminate nodules’. Emphysema was found in 65/339 (19.1%), only 5 being detected in the X-ray.

Conclusion

Volume-based CT proved to be useful in the investigation of silicosis among individuals with a relevant exposure to silica, capturing diagnoses that had not been identified on X-rays. A response gradient of silicosis was showed by CT even in this population with ILO category 0 radiographs. It can be indicated based on quantitative and/or qualitative criteria of occupational exposure, especially considering the possibilities of low CT dosage.

Another One Fights the Dust - Targeting the NLRP3 Inflammasome for the Treatment of Silicosis

Silicosis is a multifaceted lung disease, characterised by persistent inflammation and structural remodelling. Despite its poor prognosis, there are no treatments currently available for patients with silicosis. Recent pre-clinical findings in models of lung fibrosis have suggested a major role for the nucleotide binding domain and leucine-rich repeat pyrin domain containing 3 (NLRP3) inflammasome in silica-driven inflammation and fibrosis. This review outlines the beneficial effects of targeting the NLRP3 inflammasome in in vitro cell experiments and in in vivo animal models, whereby inflammation and fibrosis are abrogated following NLRP3 inflammasome inhibition. While preclinical evidence is promising, studies which explore NLRP3 inflammasomes in the clinical setting are warranted. In particular, there is still a need to identify biomarkers which may be helpful for the early detection of silicosis and to fully elucidate mechanisms underlying these beneficial effects to further develop or repurpose existing anti-NLRP3 drugs as novel treatments that limit disease progression.

The Impact of Ambient Environmental and Occupational Pollution on Respiratory Diseases

Ambient pollutants and occupational pollutants may cause and exacerbate various lung and respiratory diseases. This review describes lung and respiratory diseases in relation to ambient pollutants, particularly particulate matter (PM2.5), and occupational air pollutants, excluding communicable diseases and indoor pollutants, including tobacco smoke exposure. PM2.5 produced by combustion is an important ambient pollutant. PM2.5 can cause asthma attacks and exacerbations of chronic obstructive pulmonary disease in the short term. Further, it not only carries a risk of lung cancer and death, but also hinders the development of lung function in children in the long term. It has recently been suggested that air pollution, such as PM2.5, is a risk factor for severe coronavirus disease (COVID-19). Asbestos, which causes asbestosis, lung cancer, and malignant mesothelioma, and crystalline silica, which cause silicosis, are well-known traditional occupational pollutants leading to pneumoconiosis. While work-related asthma (WRA) is the most common occupational lung disease in recent years, many different agents cause WRA, including natural and synthetic chemicals and irritant gases. Primary preventive interventions that increase awareness of pollutants and reduce the development and exacerbation of diseases caused by air pollutants are paramount to addressing ambient and occupational pollution.