title: Right middle lobe atelectasis associated with endobronchial silicotic lesions.
abstract: BACKGROUND
  In a period of 18 months, we have encountered 4 cases of right middle lobe atelectasis associated with endobronchial silicotic lesions of right middle lobe bronchi. All patients had occupational exposure to mineral dusts (3 coal miners and 1 sand blaster) for months to decades.
  
  
  METHODS
  The nature of the endobronchial silicotic lesions that caused the bronchial obstruction has been confirmed by endobronchial biopsies and energy-dispersive spectrometry of the lesions. Extrinsic compression has been excluded by careful radiographic and computed tomographic image analysis.
  
  
  RESULTS
  The endobronchial silicosis does not appear to correlate with the degree of pneumoconiosis of the lung parenchyma. The endobronchial silicosis may cause bronchial obstruction in the absence of radiographic evidence of pulmonary silicosis.
  
  
  CONCLUSIONS
  The endobronchial silicosis and consequent lung atelectasis may be associated with silica exposure.
authors.affiliation: Taiwan Provincial Chronic Disease Control Bureau, Wan-Shun-Liau, Shen-King Shiang, Taipei County, Taiwan.
authors.forename: H P
authors.initials: HP
authors.lastname: Chien
authors.forename: T P
authors.initials: TP
authors.lastname: Lin
authors.forename: H L
authors.initials: HL
authors.lastname: Chen
authors.forename: T W
authors.initials: TW
authors.lastname: Huang
mesh_terms: D000368:Aged; D001982:Bronchial Diseases / Q000209:etiology / Q000473:pathology*; D003031:Coal / Q000009:adverse effects; D004391:Dust / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D008878:Middle Lobe Syndrome / Q000209:etiology / Q000473:pathology*; D016273:Occupational Exposure / Q000009:adverse effects; D012829:Silicosis / Q000209:etiology / Q000473:pathology*
chemical_list: D003031:Coal; D004391:Dust