Inhalational Talc Pneumoconiosis: Radiographic and CT Findings in 14 Patients

Thoracic Applications of Spectral CT Scan

TOPIC IMPORTANCE

Thoracic imaging with CT scan has become an essential component in the evaluation of respiratory and thoracic diseases. Providers have historically used conventional single-energy CT; however, prevalence of dual-energy CT (DECT) is increasing, and as such, it is important for thoracic physicians to recognize the utility and limitations of this technology.

REVIEW FINDINGS

The technical aspects of DECT are presented, and practical approaches to using DECT are provided. Imaging at multiple energy spectra allows for postprocessing of the data and the possibility of creating multiple distinct image reconstructions based on the clinical question being asked. The data regarding utility of DECT in pulmonary vascular disorders, ventilatory defects, and thoracic oncology are presented. A pictorial essay is provided to give examples of the strengths associated with DECT.

SUMMARY

DECT has been most heavily studied in chronic thromboembolic pulmonary hypertension; however, it is increasingly being used across a wide spectrum of thoracic diseases. DECT combines morphologic and functional assessments in a single imaging acquisition, providing clinicians with a powerful diagnostic tool. Its role in the evaluation and treatment of thoracic diseases will likely continue to expand in the coming years as clinicians become more experienced with the technology.

Noninfectious Granulomatous Lung Disease: Radiological Findings and Differential Diagnosis

Granulomatous lung diseases (GLDs) are a heterogeneous group of pathological entities that can have different clinical presentations and outcomes. Granulomas are histologically defined as focal aggregations of activated macrophages, Langerhans cells, and lymphocytes, and may form in the lungs when the immune system cannot eliminate a foreign antigen and attempts to barricade it. The diagnosis includes clinical evaluation, laboratory testing, and radiological imaging, which especially consists of high-resolution computed tomography. bronchoalveolar lavage, transbronchial needle aspiration or cryobiopsy, positron emission tomography, while genetic evaluation can improve the diagnostic accuracy. Differential diagnosis is challenging due to the numerous different imaging appearances with which GLDs may manifest. Indeed, GLDs include both infectious and noninfectious, and necrotizing and non-necrotizing granulomatous diseases and the imaging appearance of some GLDs may mimic malignancy, leading to confirmatory biopsy. The purposes of our review are to report the different noninfectious granulomatous entities and to show their various imaging features to help radiologists recognize them properly and make an accurate differential diagnosis.

Fatal Excipients: An Autopsy Case Series of Excipient Lung Disease

ABSTRACT

Crushed oral tablets, when injected intravenously, may induce a foreign body granulomatous reaction in and around pulmonary arterioles, because of the presence of filler materials (excipients). This typically presents as shortness of breath in the context of pulmonary hypertension with arteriolar dilation and centrilobular nodules on imaging modalities. The constellation of findings may be overlooked or misdiagnosed by clinicians and pathologists, ultimately affecting patient care and postmortem assessment. We describe 5 patients with excipient lung disease that had antemortem chronic medical conditions that required a peripherally inserted catheter or port. All 5 patients had intravascular and perivascular deposition of polarizable foreign material within the pulmonary arteries. Foreign body granulomatosis as a result of intravenous drug use was not clinically suspected in any patient, and 2 of the 5 patients were misdiagnosed with mycobacterium infections. Pulmonary congestion, dyspnea, and symptoms of heart failure were noted in 3 patients and 2 had a history of upper arm deep vein thrombosis. We conclude that excipient lung disease may be underdiagnosed cause of dyspnea, pulmonary hypertension, and death in patients with a known history of intravenous drug use.

ERA Merewether - And asbestos

After a succession of posts and studying for the Bar, Edward Merewether joined the Medical Inspectorate of Factories in 1927. Not long thereafter he was asked to undertake a study of the effects of asbestos exposure on the lungs. His results showed that asbestos workers had a significant risk of developing pulmonary fibrosis and this resulted in the promulgation of regulations to limit exposure. Some years later, Merewether showed that asbestos workers also had a higher than expected risk of developing lung cancer, but on this occasion there was no further protective legislation, and the association was not generally accepted until some years later. Merewether's name is inextricably linked with the risks of asbestos exposure but after his death the importance of his efforts was often played down by those who wished to show that the government had not acted quickly enough, or vigorously enough to control the hazard. The contention of this paper is that these criticisms are not justified and that Merewether acted to the best of his ability, given the conditions and knowledge current at the time he was working.

Imaging diagnosis of classical and new pneumoconiosis: predominant reticular HRCT pattern

Our understanding of the manifestations of pneumoconioses is evolving in recent years. Associations between novel exposures and diffuse interstitial lung disease have been newly recognized. In advanced asbestosis, two types of fibrosis are seen, probably related to dose of exposure, existence of pleural fibrosis, and the host factor status of the individual. In pneumoconiosis of predominant reticular type, nodular opacities are often seen in the early phase. The nodular pattern is centrilobular, although some in metal lung show perilymphatic distribution, mimicking sarcoidosis. High-resolution computed tomography enables a more comprehensive correlation between the pathologic findings and clinically relevant imaging findings. The clinician must understand the spectrum of characteristic imaging features related to both known dust exposures and to historically recent new dust exposures.

Noninfectious Granulomatous Diseases of the Chest

Granulomas are pathologically defined as focal aggregations of activated macrophages, Langerhans cells, and lymphocytes. Granulomas form in the lungs when the immune system barricades the substances it perceives as foreign but is unable to remove. Granulomas manifest with numerous imaging appearances in thoracic radiology, and their presence is a nonspecific finding. Granulomatous lung diseases comprise multiple entities with variable clinical manifestations and outcomes. Their imaging findings are rarely specific and can mimic malignancies, often triggering an extensive diagnostic workup. Radiologists must be familiar with the clinical manifestations and imaging findings of these entities to generate appropriate differential diagnoses. This review describes the imaging manifestations of various noninfectious, necrotizing, and nonnecrotizing granulomatous diseases that primarily affect the thorax. ^©RSNA, 2020.

An unusual cause of breathlessness and profuse micronodules

We describe a 21-year-old male with a history of smoking and subacute onset of breathlessness with normal cardiorespiratory examination. The presence of "track marks" and digital infarcts prompted evaluation for infective endocarditis and confrontational history taking revealed anorexia, weight loss over 3 months along with intravenous drug abuse of reconstituted tablets of tapentadol. Echocardiography was normal and blood cultures were sterile; computed tomography showed bilateral, diffuse, small centrilobular nodules with "tree-in-bud" appearance. In this clinicopathologic conference, we discuss the clinical and radiological differential diagnosis of centrilobular nodules, lung biopsy findings, and management options for patients with such a presentation.

Imaging of Occupational Lung Disease

Occupational lung diseases span a variety of pulmonary disorders caused by inhalation of dusts or chemical antigens in a vocational setting. Included in these are the classic mineral pneumoconioses of silicosis, coal worker's pneumoconiosis, and asbestos-related diseases as well as many immune-mediated and airway-centric diseases, and new and emerging disorders. Although some of these have characteristic imaging appearances, a multidisciplinary approach with focus on occupational exposure history is essential to proper diagnosis.

Inhalation of Talc Induces Infiltration of Macrophages and Upregulation of Manganese Superoxide Dismutase in Rats

Talc is a mineral that is widely used in cosmetic products, antiseptics, paints, and rubber manufacturing. Although the toxicological effects of talc have been studied extensively, until now no detailed inhalation study of talc focusing on oxidative stress has been done. This repeated 4 weeks whole-body inhalation toxicity study of talc involved Sprague-Dawley rats. Male and female groups of rats were exposed to inhaled talc at 0, 5, 50, and 100 mg/m(3) for 6 hours daily, 5 days/week for 4 weeks. The objective was to identify the 4-week inhalation toxicity of talc and investigate antioxidant activity after exposure to talc. There were no treatment-related symptoms or mortality in rats treated with talc. Glucose (GLU) was decreased significantly in male rats exposed to 50 and 100 mg/m(3) of talc. Histopathological examination revealed infiltration of macrophages on the alveolar walls and spaces near the terminal and respiratory bronchioles. In male and female rats exposed to 100 mg/m(3) talc, expression of superoxide dismutase 2, a typical biological indicator of oxidative damage, was significantly increased. Thus, inhalation of talc induces macrophage aggregations and oxidative damage in the lung.

Pulmonary effects of i.v. injection of crushed oral tablets: "excipient lung disease"

OBJECTIVE

When crushed oral tablets are injected i.v., their filler material (excipient) can induce a potentially fatal foreign-body reaction in pulmonary arterioles, presenting as dyspnea and pulmonary hypertension with centrilobular nodules on CT. We will describe the imaging and pathologic features of "excipient lung disease."

CONCLUSION

The radiologist has a critical role in recognizing and reporting excipient lung disease because the referring clinician may be unaware of the patient's i.v. drug abuse.

Talcosis in soapstone artisans: high-resolution CT findings in 12 patients

AIM

To describe the high-resolution computed tomography (HRCT) features of pneumoconiosis observed in soapstone artisans.

MATERIALS AND METHODS

The present study included 12 soapstone artisans with chest radiography abnormalities consistent with the diagnosis of pneumoconiosis, in accordance with the International Labour Office classification. All patients had undergone HRCT, and the images were retrospectively analysed by two chest radiologists, who reached decisions in consensus.

RESULTS

All patients presented with interlobular septal thickening. Small centrilobular nodules (75%) and ground-glass opacities (67%) were also common findings. The distributions of abnormalities were predominantly diffuse. No pleural abnormality was found.

CONCLUSION

The HRCT abnormalities observed in this group of soapstone artisans are similar to those of pure talc pneumoconiosis.

Pulmonary talcosis 10 years after brief teenage exposure to cosmetic talcum powder

Pulmonary talcosis is a rare but debilitating variant of pneumoconiosis often presenting with isolated non-specific symptoms of progressive exertional dyspnoea or cough. Occupational exposure to talc dust and intravenous drug abuse are well-recognised aetiological factors with only a few cases related to cosmetic talc exposure being reported to date. The authors report a case of a young woman in whom a mere 4 month ritual of inhaling cosmetic talcum powder led to full-blown pulmonary talcosis being diagnosed 10 years later. The importance of a taking a pertinent history relating to environmental exposures in all patients presenting with respiratory symptoms is re-established here.

Pulmonary talcosis: imaging findings

Talc is a mineral widely used in the ceramic, paper, plastics, rubber, paint, and cosmetic industries. Four distinct forms of pulmonary disease caused by talc have been defined. Three of them (talcosilicosis, talcoasbestosis, and pure talcosis) are associated with aspiration and differ in the composition of the inhaled substance. The fourth form, a result of intravenous administration of talc, is seen in drug users who inject medications intended for oral use. The disease most commonly affects men, with a mean age in the fourth decade of life. Presentation of patients with talc granulomatosis can range from asymptomatic to fulminant disease. Symptomatic patients typically present with nonspecific complaints, including progressive exertional dyspnea, and cough. Late complications include chronic respiratory failure, emphysema, pulmonary arterial hypertension, and cor pulmonale. History of occupational exposure or of drug addiction is the major clue to the diagnosis. The high-resolution computed tomography (HRCT) finding of small centrilobular nodules associated with heterogeneous conglomerate masses containing high-density amorphous areas, with or without panlobular emphysema in the lower lobes, is highly suggestive of pulmonary talcosis. The characteristic histopathologic feature in talc pneumoconiosis is the striking appearance of birefringent, needle-shaped particles of talc seen within the giant cells and in the areas of pulmonary fibrosis with the use of polarized light. In conclusion, computed tomography can play an important role in the diagnosis of pulmonary talcosis, since suggestive patterns may be observed. The presence of these patterns in drug abusers or in patients with an occupational history of exposure to talc is highly suggestive of pulmonary talcosis.