Uncommon Occupational Lung Diseases: High-Resolution CT Findings

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1 ardiopulmonary Imaging Pictorial ssay Flors et al. HRT of Occupational Lung iseases ardiopulmonary Imaging Pictorial ssay Lucía Flors 1 Maria L. omingo 1 arlos Leiva-Salinas 1 Miguel Mazón 1 sther Roselló-Sastre 2 José Vilar 1 Flors L, omingo ML, Leiva-Salinas, Mazón M, Roselló-Sastre, Vilar J Keywords: high-resolution T, occupational lung diseases OI: /JR Received February 16, 2009; accepted after revision June 21, epartment of Radiology, Hospital Universitario octor Peset, vd. Gaspar guilar 90, Valencia 46017, Spain. ddress correspondence to L. Flors lasco (flors_luc@gva.es). 2 epartment of Pathology, Hospital Universitario octor Peset, Valencia, Spain. W This is a Web exclusive article. M This article is available for M credit. See for more information. JR 2010; 194:W20 W X/10/1941 W20 merican Roentgen Ray Society Uncommon Occupational Lung iseases: High-Resolution T Findings OJTIV. The purpose of this article is to describe the high-resolution T (HRT) features of uncommon occupational lung diseases. ONLUSION. HRT plays an increasing role in the evaluation of occupational lung diseases. We present several cases of unusual occupational lung diseases and their HRT findings. The diseases studied were siderosis, talcosis, berylliosis, calcicosis, hypersensitivity pneumonitis (due to wheat flour and isocyanates), and rdystil syndrome. The characteristic HRT findings together with clinical features and related occupational history improve the diagnostic accuracy of these diseases. O ccupational lung diseases represent a frequently diagnosed workrelated condition. High-resolution T (HRT) is fundamental for the quantification of disease severity and the prognosis and identification of coexisting or alternative diseases. However, no standardized quantification scheme is available for occupational lung diseases using T. The HRT features of silicosis, asbestosis, and coal-worker pneumoconiosis have been widely described. The aim of this article is to describe and illustrate the HRT features of patients with uncommon occupational lung diseases. Siderosis Siderosis is caused by the accumulation of iron oxide in macrophages within the lung [1]. Most cases of siderosis are seen in electric-arc and oxyacetylene welders who may inhale finely divided particles of iron oxide [2, 3]. Siderosis is not usually associated with fibrosis or functional impairment [1, 2, 4]. The radiologic abnormalities are reversible and may resolve partially or completely after exposure ceases [2, 3]. HRT shows widespread ill-defined small centrilobular nodules and, less commonly, patchy areas of ground-glass attenuation without zonal predominance [1, 2] (Fig. 1). mphysema is often seen [1]. The micronodules on T correspond to dust macules, which are collections of dust-laden macrophages aggregated along the perivascular and peribronchial lymphatic vessels [1]. Inhaled iron with silica results in silicosiderosis (mixed-dust pneumoconiosis) [1, 2] (Fig. 2). Silicosiderosis is seen in individuals involved in the mining and processing of iron ores, workers in iron and steel rolling mills, and foundry workers. Talcosis Talc is a hydrated magnesium silicate used in the leather, ceramic, paper, plastics, rubber, building, paint, and cosmetic industries [1]. Talc exposure may occur as a result of inhalation or by IV administration [1], which occurs most often during recreational drug use. Talc causes a nonnecrotizing granulomatous inflammation that leads to progressive fibrosis [1, 5]. HRT findings in patients with talcosis caused by inhaled particulates include small centrilobular and subpleural nodules and heterogeneous conglomerate masses with internal foci of high attenuation that correspond to talc deposition [1, 5, 6] (Fig. 3). erylliosis xposure to beryllium occurs in a variety of industries: aerospace, ceramics, dentistry and dental supplies, nuclear weapons and reactors, and several others [7]. There are two distinct types of lung injury related to beryllium exposure: an acute chemical pneumonitis and a chronic granulomatous disease [7]. cute berylliosis has become rare because of modern industrial control measures [1]. hronic beryllium disease represents a gran- W20 JR:194, January 2010

2 HRT of Occupational Lung iseases ulomatous hypersensitivity response, and its incidence and severity are not always related to the intensity and duration of exposure [7]. It has been associated with pulmonary carcinoma [1]. The histology of chronic beryllium disease is indistinguishable from that of sarcoid osis [7]. diagnosis of chronic beryllium disease requires a lung biopsy proving granulomatous inflammation and evidence of sensitivity to beryllium shown at blood testing or in bronchoalveolar lavage fluid [1, 7]. HRT findings of berylliosis are similar to those of granulomatous lung diseases [1]. The most common findings are parenchymal small nodules [1] often clustered around the bronchi, interlobular septa, or in the subpleural region where the nodules may form pseudoplaques [7] and interlobular septal thickening [1, 7]. Other findings include ground-glass opacities, honeycombing, conglomerate mass, bronchial wall thickening [7], and hilar or mediastinal lymph nodes [1] with amorphous or eggshell calcification [7] (Fig. 4). alcicosis alcicosis is caused by inhaling limestone dust. Limestone consists predominantly of calcium carbonate but may also contain magnesium oxide, silica dioxide, and aluminum oxide [8, 9]. Pure limestone itself does not cause pneumoconiosis [8, 9]. alcicosis is uncommon, and its correct diagnosis requires an accurate histology study and an appropriate occupational history. The nodules show a foreign-body granulomatous response with several foreign-body cells. Light microscopy reveals the presence of numerous birefringent crystals with a chemical composition consistent with limestone [8]. HRT findings have not been well established. Widespread small nodules have been described [8] (Fig. 5). Hypersensitivity Pneumonitis Hypersensitivity pneumonitis, also called extrinsic allergic alveolitis, is a worldwide immunologic occupational lung disease. Numerous organic dusts of plant or animal origin and some chemicals can cause hypersensitivity pneumonitis [2]. Humoral (type III) and cell-mediated (type IV) immune responses play a role in pathogenesis, resulting in alveolitis and granuloma formation [2, 10]. Farmer s lung and bird fancier s lung remain the most prevalent forms of the disease. Grain and flour have been associated with hypersensitivity pneumonitis. It has been described in flour mill workers because of contamination with wheat weevils (Sitophilus species) [10] (Fig. 6). Isocyanate vapors and aerosols also induce hypersensitivity pneumonitis. They are used for the large-scale production of polyurethane polymers, widely used in industry [10]. lthough isocyanates are not organic dusts, the hypersensitivity pneumonitis they cause is identical to organic dust related hypersensitivity pneumonitis [2] (Fig. 7). linical, pathologic, and radiologic features are similar in most cases of hypersensitivity pneumonitis. The characteristic HRT manifestations in acute hypersensitivity pneumonitis consist of air-space consolidations [2, 10]. Findings in subacute hypersensitivity pneumonitis are patchy areas of ground-glass attenuation (Fig. 6) and small centrilobular nodules [2, 11] (Fig. 7). Other findings are focal air trapping (Fig. 6) on expiratory scans and cystic spaces presumably caused by partial bronchiolar obstruction [10, 11]. hronic hypersensitivity pneumonitis is characterized by the presence of fibrosis superimposed on findings of acute or subacute hypersensitivity pneumonitis [2, 10, 11] (Fig. 7). Relative sparing of the lung bases usually allows its distinction from idiopathic pulmonary fibrosis [2, 10]. rdystil Syndrome rdystil syndrome was first described in 1992 when an outbreak of organizing pneumonia occurred among textile printing sprayers in factories in the autonomous community of Valencia, Spain. n epidemiologic investigation proposed that the lung disease was caused by spraying procedures that delivered a respirable aerosol of cramin- FWN (ayer Healthare) to distal airways and pulmonary parenchyma. cramin-fwn is a polyamidoamine that is applied with a brush or sponge for textile printing [12, 13]. The organizing pneumonia caused by the inhalation of cramin-fwn is characterized by a tendency to evolve into progressive interstitial fibrosis despite the use of corticosteroids. The illness is restricted to the respiratory system and, once respiratory failure has developed, the prognosis is poor [12]. HRT findings showed two different patterns: patchy areas of air-space consolidation with subpleural distribution, similar to idiopathic forms of organizing pneumonia, or multiple small nodular opacities as the predominant radiographic finding [12] (Fig. 8). In patients with a progressive course, an added coarse reticular pattern, more consistent with chronic interstitial pneumonia, was observed later [12]. onclusion In the presence of a history of exposure and consistent clinical features, the diagnosis of an uncommon occupational lung disease can be suggested by the characteristic described HRT findings. References 1. hong S, Lee KS, hung MJ, Han J, Kwon OJ, Kim TS. Pneumoconiosis: comparison of imaging and pathologic findings. RadioGraphics 2006; 26: Kim KI, Kim W, Lee MK, et al. Imaging of occupational lung disease. RadioGraphics 2001; 21: kira M. Uncommon pneumoconiosis: T and pathologic findings. Radiology 1995; 197: Han, Goo JM, Im JG, et al. Findings of arcwelders pneumoconiosis. Korean J Radiol 2000; 1: kira M. Other uncommon pneumoconioses. In: Genevois, e Vust P, eds. Imaging of occupational and environmental disorders of the chest. erlin, Germany: Springer-Verlag, 2006: Marchiori, Souza Júnior S, Müller NL. Inhalation pulmonary talcosis: high-resolution T findings in 3 patients. J Thorac Imaging 2004; 19: Lynch. Imaging of beryllium-related diseases. In: Genevois, e Vust P, eds. Imaging of occupational and environmental disorders of the chest. erlin, Germany: Springer-Verlag, 2006: rummy F, arl I, ameron, Heaney LG. possible case of pneumoconiosis in a limestone quarry worker. Occup Med (Lond) 2004; 54: oig T. isabling pneumoconiosis from limestone dust. r J Ind Med 1955; 12: rauner MW, rillet PY, Guillon F. Hypersensitivity pneumonitis. In: Genevois, e Vust P, eds. Imaging of occupational and environmental disorders of the chest. erlin, Germany: Springer- Verlag, 2006: Silva I, hurg, Müller NL. Hypersensivity pneumonitis: spectrum of high-resolution T and pathologic findings. JR 2007; 188: Romero S, Hernández L, Gil J, randa I, Martín, Sanchez-Payá J. Organizing pneumonia in textile printing workers: a clinical description. ur Respir J 1998; 11: amus PH, Nemery. novel cause for bronchiolitis obliterans organizing pneumonia: exposure to paint aerosols in textile workshops. ur Respir J 1998; 11: JR:194, January 2010 W21

3 Flors et al. Fig. 1 Siderosis in 39-year-old man with 30 pack-year smoking history and 20 years of exposure to arc-welding who presented complaining of cough., High-resolution T images (1-mm-thick sections) show multiple small and poorly defined centrilobular nodules in upper lobe of both lungs (black arrows, and ). entrilobular emphysema (white arrows, and ) and areas of ground-glass attenuation (asterisks, ) in dependent zones are seen. Results of pulmonary function test were normal., Photomicrograph after bronchoalveolar lavage shows marked iron overload in alveolar macrophages, pathologic confirmation of siderosis. (Prussian blue iron stain, 60) F Fig. 2 Silicosiderosis in 65-yearold man with 40 pack-year smoking history who worked for 40 years in foundry with metals and sand. F, High-resolution T images ( ) show widespread centrilobular nodules (black arrows, and ) and conglomerated masses (asterisks, and ) with loss of volume in upper lobes. Mediastinal window T images ( and F) show calcification of mediastinal and hilar lymph nodes (white arrows). W22 JR:194, January 2010

4 HRT of Occupational Lung iseases Fig. 3 Talcosis in 71-year-old woman who worked for 11 years in magnesium silicate processing., High-resolution T images ( ) show small centrilobular nodules (black arrows, and ) and conglomerated masses (asterisks, ) in upper lobes. When viewed at mediastinal windows (level, 10 HU; width, 300 HU) ( and ), masses are seen to contain high-attenuation material (white arrows), also seen in mediastinal lymph nodes (black arrow, ). F, Photomicrograph after lung fine-needle aspiration biopsy shows talc crystals in cytoplasm of alveolar macrophages, pathologic confirmation of talcosis. (ifferential staining, 60) F JR:194, January 2010 W23

5 Flors et al. Fig year-old man, who worked with dental supplies for 20 years, with advanced chronic beryllium disease. F, High-resolution T images show multiple small nodules (arrowheads, ), predominantly subpleural and conglomerate masses (asterisk, and F) associated with interlobular septal thickening (open arrows, ), marked distortion and dilation of segmental bronchi (black arrows, ), and upper lobe volume loss. lso seen are area of ground-glass attenuation with reticulation and honeycombing (curved arrow, ), hilar and mediastinal lymph nodes with eggshell calcification (white arrows, and ), and left hilar mass (asterisk, F) with invasion of left inferior pulmonary vein. pulmonary transbronchial biopsy showed the presence of fibrosing granulomas. F Fig. 5 alcicosis in 52-year-old man who was marble worker for 16 years., High-resolution T images ( ) show small diffuse nodules (arrows, and ) and some subpleural compounding pseudoplaques (arrowheads, and ). Mediastinal window T image (level, 10 HU; width, 300 HU) () shows pseudoplaques and mediastinal lymph nodes with high attenuation and punctate calcifications (asterisks, ). W24 JR:194, January 2010

6 HRT of Occupational Lung iseases Fig. 6 Subacute phase of hypersensitivity pneumonitis due to wheat flour in 40-year-old man who was flour mill worker and presented with cough and dyspnea., High-resolution T images show geographical ground-glass opacity with interlobular septal thickening (crazy-paving pattern) (asterisks, and ) with some lucent lobules (arrows, and ), predominantly in lower lobes. Fig. 7 Hypersensitivity pneumonitis due to occupational exposure to isocyanates. and, High-resolution T images show widespread small centrilobular nodules (arrows, ) in 45-year-old woman who was furniture polisher. Findings show subacute phase of hypersensitivity pneumonitis., High-resolution T images show findings of fibrosis predominantly in upper lobes: traction bronchiectasis (black arrow, ) and traction bronchiolectasis (curved arrow, ) as well as areas of ground-glass attenuation (asterisk, and ) and subpleural honeycombing (arrowhead, ) in 55-year-old man who was smoker and worker in plastic industry. Findings show chronic phase of hypersensitivity pneumonitis. JR:194, January 2010 W25

7 Flors et al. FOR YOUR INFORMTION Fig. 8 rdystil syndrome in 40-year-old woman who was textile printing worker. High-resolution T image shows small diffuse centrilobular nodules. Transbronchial biopsy showed changes of organizing pneumonia. This article is available for M credit. See for more information. W26 JR:194, January 2010