title: Fibrosing Bronchiolitis Evolving from Infectious or Inhalational Acute Bronchiolitis. A Reversible Lesion.
abstract: BACKGROUND
  Occasional cases of bronchiolitis show pathologic features somewhat suggestive of constrictive bronchiolitis, but with granulation tissue plugs that variably occlude the lumen in a pattern more typical of organizing pneumonia. These cases are poorly defined in the literature and the course of patients with this pattern of disease is unclear.
  
  
  OBJECTIVE
  To describe an uncommon and potentially treatable pattern of acute bronchiolitis that has been termed fibrosing bronchiolitis.
  
  
  RESULTS
  We report three patients with respiratory failure and acute onset of probable infectious or inhalational bronchiolitis that was characterized by centrilobular nodules and a variable tree-in-bud appearance on computed tomography. All patients showed an uncommon pattern of bronchiolitis on surgical lung biopsy. The pathologic abnormalities were confined to the bronchioles and consisted of reepithelialized, partially collagenized and variably polypoid plugs of granulation tissue that narrowed the bronchiolar lumens. All three patients improved dramatically on immunosuppressive therapy.
  
  
  CONCLUSIONS
  These cases of fibrosing bronchiolitis represent an uncommon pattern of acute bronchiolitis that is reversible if detected at an early stage. Early recognition and treatment may prevent development of permanent bronchiolar fibrosis.
authors.affiliation: 1 Department of Medicine.|2 Centre for Heart Lung Innovation.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Ryerson
authors.affiliation: 3 Prince George Regional Hospital, Prince George, British Columbia, Canada.
authors.forename: Sharla-Rae
authors.initials: SR
authors.lastname: Olsen
authors.affiliation: 1 Department of Medicine.
authors.forename: Chris
authors.initials: C
authors.lastname: Carlsten
authors.affiliation: 4 Department of Radiology, and.
authors.forename: Carol
authors.initials: C
authors.lastname: Donagh
authors.affiliation: 4 Department of Radiology, and.
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Bilawich
authors.affiliation: 5 Department of Medicine, University of Calgary, Calgary, Alberta, Canada; and.
authors.forename: Stephen K
authors.initials: SK
authors.lastname: Field
authors.affiliation: 6 Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada.|7 Department of Pathology, Vancouver General Hospital, Vancouver, British Columbia, Canada.
authors.forename: Andrew
authors.initials: A
authors.lastname: Churg
mesh_terms: D000328:Adult; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D001706:Biopsy; D001989:Bronchiolitis Obliterans / Q000188:drug therapy* / Q000473:pathology*; D018549:Cryptogenic Organizing Pneumonia / Q000473:pathology*; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011241:Prednisone / Q000627:therapeutic use*; D011658:Pulmonary Fibrosis / Q000473:pathology*; D014057:Tomography, X-Ray Computed
chemical_list: D000893:Anti-Inflammatory Agents; D011241:Prednisone
keywords: bronchiolitis; bronchiolitis obliterans; constrictive bronchiolitis; diffuse lung disease; interstitial lung disease