title: [Caplan's syndrome: rarely presenting as <<pulmorenal>> syndrome].
abstract: METHODS
  A 59-year-old man complained about having dry cough for months and a recent sudden onset of minor hemoptoe, asymmetric arthritis, myalgia as well as lack of appetite. He presented an occupational history of 12-year exposure to an organic dust as uranium miner in German Democratic Republic followed by 21 years as heavy construction worker in Germany and in Switzerland. Laboratory work-up tested positive for microhematuria and anti-neutrophilic cytoplasmic antibodies (ANCA). Chest X-rays and CT scan showed bilaterally scattered nodules. Thoracoscopic wedge resection was performed, histopathological analysis revealed granuloma with central necrotic area containing black coal dust and silica depositions surrounded by histiocytes. The pulmonary opacities on X-ray and the typical histology in the light of significant dust exposure allow the diagnosis of a Caplan's syndrome.
  
  
  METHODS
  The symptoms improved rapidly under steroid therapy. Further investigations revealed a clear renal cell carcinoma as a cause for the persistent microhematuria.
  
  
  CONCLUSIONS
  Rheumatoid arthritis, pulmonary nodules and history of prolonged dust exposure are classical findings that define Caplan's syndrome. These patients present with different immunological phenomena - in our case ANCA-positivity without vasculitis. Interestingly, the renal cell carcinoma which led to the "pulmorenal" syndrome in our patient is another health problem overrepresented in uranium mine workers.
authors.affiliation: Klinik und Poliklinik für Innere Medizin, Universitätsspital Zürich.
authors.forename: Albina
authors.initials: A
authors.lastname: Nowak
authors.affiliation: Rheumaklinik, Universitätsspital Zürich.
authors.forename: Katja
authors.initials: K
authors.lastname: Göhner
authors.affiliation: Klinik für Nephrologie, Universitätsspital Zürich und Klinik für Nieren- und Hochdruckerkrankungen und Klinische Immunologie, Klinikum Harlaching des Städtischen Klinikums München, Deutschland.
authors.forename: Clemens D
authors.initials: CD
authors.lastname: Cohen
mesh_terms: D019268:Antibodies, Antineutrophil Cytoplasmic / Q000032:analysis; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000473:pathology; D001706:Biopsy; D002205:Caplan Syndrome / Q000175:diagnosis* / Q000473:pathology; D002292:Carcinoma, Renal Cell / Q000175:diagnosis / Q000473:pathology; D015897:Comorbidity; D003937:Diagnosis, Differential; D006801:Humans; D007668:Kidney / Q000473:pathology; D007680:Kidney Neoplasms / Q000175:diagnosis / Q000473:pathology; D008168:Lung / Q000473:pathology; D008297:Male; D008875:Middle Aged; D008906:Mining; D009381:Neoplasms, Radiation-Induced / Q000175:diagnosis / Q000473:pathology
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic
keywords: Caplan's syndrome; Caplan-Syndrom; anti-neutrophile zytoplasmatische Antikörper; anti-neutrophilic cytoplasmic antibodies; rheumatoid pneumoconiosis; rheumatoide Pneumokoniose