Anthracofibrosis attributed to mixed mineral dust exposure: report of three cases J-M Naccache, 1,2 I Monnet, 3 H Nunes, 1,2 M-A Billon-Galland, 4 J-C Pairon, 3 F Guillon, 1,2 D Valeyre 1,2 1 Universite ´ Paris 13, EA2363, Ho ˆpital Universitaire Avicenne, Assistance Publique–Ho ˆpitaux de Paris, Bobigny, France; 2 Service Pneumologie, Ho ˆpital Universitaire Avicenne, Assistance Publique–Ho ˆpitaux de Paris, Bobigny, France; 3 Service de Pneumologie et de Pathologie Professionnelle, Centre Hospitalier Intercommunal de Cre ´teil, Cre ´teil, France; 4 Laboratoire d’Etude des Particules Inhale ´es, Paris, France Correspondence to: Dr J-M Naccache, Service de Pneumologie, Ho ˆpital Avicenne, 125 rue de Stalingrad, 93009 Bobigny Cedex, France; jean-marc.naccache@avc. ap-hop-paris.fr Received 14 August 2006 Accepted 16 October 2006 ABSTRACT Anthracofibrosis, defined as bronchial luminal narrowing with black pigmentation of the overlying mucosa, has been attributed to tuberculosis. Three patients with anthracofibrosis without mycobacterial infection are described who had previous occupational exposure to mixed dusts. CT scans showed calcified hilar lymph nodes in two patients. Surgical biopsy in one patient and autopsy in another revealed fibrotic lymph nodes with black pigmentation. Mineralogical analysis by transmis- sion electron microscopy of pulmonary, hilar and/or bronchial samples found high levels of particle retention, raised percentages of free crystalline silica and mica in two patients, and free crystalline silica, kaolin and other silicates in the third. No evidence of any other contributory factor was found, suggesting that mixed mineral dust was the most probable cause. These observations suggest that exposure to mixed mineral dust should be added to the aetiology of anthracofibrosis. Anthracofibrosis is defined as narrowing or oblit- eration of the bronchial lumen associated with black pigmentation (anthracosis) of the overlying mucosa. 12 The main characteristics are atelectasis with bronchial stenosis surrounded by calcified or non-calcified lymph nodes on CT scans, frequent active tuberculous infection and absence of pneu- moconiosis. Silica dust-induced lung disease mainly involves the parenchyma and small airways rather than the large bronchi. 3 We describe three cases with features consistent with a diagnosis of anthra- cofibrosis as defined above. Clinical investigations excluded tuberculosis. Based on mineralogical ana- lyses, a diagnosis of anthracofibrosis attributed to mixed mineral dusts containing free crystalline silica and other silicates is proposed. CASE REPORTS Patient 1 A 66-year-old man was evaluated in February 2002 for recurrent episodes of pneumonitis. He had stopped smoking 15 years earlier (30 pack-years). He worked principally as a forklift driver in a foundry and as a solderer in a metallurgy firm. He was exposed mostly to silica and aluminium. His medical history was noteworthy for type 2 diabetes. He complained of a chronic cough with dys- pnoea. Chest auscultation detected ronchi and inspiratory wheezing in the right upper lung area. A CT scan revealed bilateral calcified hilar adeno- pathies, bronchial stenoses and subsegmental collapse in the right upper lobe (fig 1A). Fibreoptic bronchoscopy showed anthracosis and stenoses of all the bronchi predominantly in the right upper lobe (fig 1B). Histological examination of bronchial biopsy specimens revealed fibrosis of the lamina propria without granulomas. Sputum and bronchial aspirates were smear- and culture- negative for Mycobacterium tuberculosis. Pulmonary function tests and blood gas analyses revealed severe airway obstruction (forced expiratory volume in 1 s/forced vital capacity (FEV 1 /FVC) 46%) and moderate arterial hypoxaemia (PaO 2 9.3 kPa (70 mm Hg)). Echocardiography showed pulmonary hypertension which was confirmed by catheter examination (mean pulmonary arterial pressure 32 mm Hg; mean pulmonary capillary wedge pressure 7 mm Hg). Angiography revealed stenoses of the lower right and lower left pulmonary arteries (fig 1C). The patient died in September 2003 after acute pneumonitis. The autopsy showed hilar fibrosis with anthra- cosis, bronchial and vascular stenoses, but no granuloma. Mineralogical analyses by transmission electron microscopy (TEM) of lung and hilum samples showed high mineral particle counts (lung: 41 6 10 7 p/g (normal value mean (SD) 9 (8) 6 10 7 p/g); hilum: 2296 6 10 7 p/g) and raised percentages of free crystalline silica (lung: 34% (normal value mean (SD) 14.5 (9)%); hilum: 44%) and mica particles (lung: 28% (normal value mean (SD) 18.7 (10.8)%), hilum: 46%). Normal values are based on studies of non-exposed individuals from our own laboratory. A diagnosis of hilar fibrosis with anthracofibrosis and vascular compression was made and attributed to mixed mineral dust exposure. Patient 2 A 63-year-old man was investigated in February 2000 for a left lung nodule on his chest radiograph. He had never smoked. He had worked principally as a bricklayer in Morocco, where he was exposed to silica and asphalt, and in a supermarket in France. His medical history was noteworthy for hypertension. He was in his usual state of good health. A CT scan of the thorax detected a 2.5 6 4 cm nodule in the left upper lobe, with mediastinal and hilar adenopathies and subsegmental atelectasis in the right middle lobe. Bronchoscopic examination showed diffuse inflammatory mucosa with muco- sal anthracosis and stenosis of the left upper lobe bronchus. Bronchial biopsies were non-informa- tive. Mediastinoscopy revealed hard nodes with sclerohyaline formation, calcifications and anthra- cosis. Wedge resection of a scleronecrotic nodule by thoracotomy found no granulomatosis or malig- nancy. All the samples (sputum, bronchial aspirates, lung specimens) were smear- and culture-negative Case report Thorax 2008;63:655–657. doi:10.1136/thx.2006.070243 655 on June 5, 2020 by guest. Protected by copyright. http://thorax.bmj.com/ Thorax: first published as 10.1136/thx.2006.070243 on 27 June 2008. Downloaded from