title: Update on Pulmonary Fibrosis: Not All Fibrosis Is Created Equally.
abstract: BACKGROUND
  Three distinct patterns of pulmonary fibrosis, including usual interstitial pneumonia, fibrotic nonspecific interstitial pneumonia, and airway-centered fibrosis, can be identified on surgical lung biopsies.
  
  
  OBJECTIVE
  To compare the pathologic definitions, clinical and radiographic presentations, etiologies and differential diagnoses, treatments, and prognoses of usual interstitial pneumonia, fibrotic nonspecific interstitial pneumonia, and airway-centered fibrosis patterns, and to address the challenges and controversies related to pulmonary fibrosis.
  
  
  METHODS
  Data were derived from published literature and clinical experience.
  
  
  CONCLUSIONS
  Although there may be overlap, identification of the dominant form of fibrosis in a particular case can provide a general category of disease and assist in identifying an etiology.
authors.affiliation: From the Department of Laboratory Medicine and Pathology, Mayo Clinic, Scottsdale, Arizona.
authors.forename: Maxwell L
authors.initials: ML
authors.lastname: Smith
mesh_terms: D000542:Alveolitis, Extrinsic Allergic / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D001706:Biopsy; D003240:Connective Tissue Diseases / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D003937:Diagnosis, Differential; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology*; D017563:Lung Diseases, Interstitial / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D011379:Prognosis; D011658:Pulmonary Fibrosis / Q000145:classification / Q000000981:diagnostic imaging / Q000209:etiology* / Q000517:prevention & control; D011859:Radiography; D020545:Respiratory Mucosa / Q000000981:diagnostic imaging / Q000473:pathology*; D009626:Terminology as Topic