Difference between revisions of "Diffuse alveolar damage"

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| Caption    = Hyaline membranes. [[H&E stain]].
| Caption    = Hyaline membranes. [[H&E stain]].
| Synonyms  =
| Synonyms  =
| Micro      =
| Micro      = dependent on phase - ''exudative'': hyaline membranes; ''proliferative'': interstitial thickening, inflammation (lymphocytes), type 2 pneumocyte hyperplasia, edema, Masson bodies in the airway, hyaline material (usu. focal); ''fibrotic'': interstitial inflammation, interstitial fibrosis
| Subtypes  =
| Subtypes  = exudative, proliferative, fibrotic
| LMDDx      =
| LMDDx      = [[organizing pneumonia]] (especially for ''proliferative phase DAD''), [[bronchiolitis obliterans]]
| Stains    =
| Stains    =
| IHC        =
| IHC        =

Revision as of 09:05, 18 April 2014

Diffuse alveolar damage
Diagnosis in short

Hyaline membranes. H&E stain.

LM dependent on phase - exudative: hyaline membranes; proliferative: interstitial thickening, inflammation (lymphocytes), type 2 pneumocyte hyperplasia, edema, Masson bodies in the airway, hyaline material (usu. focal); fibrotic: interstitial inflammation, interstitial fibrosis
Subtypes exudative, proliferative, fibrotic
LM DDx organizing pneumonia (especially for proliferative phase DAD), bronchiolitis obliterans
Site lung - see diffuse lung diseases

Prognosis often poor, dependent on severity and comorbidities
Clin. DDx acute respiratory distress syndrome (ARDS), acute interstitial pneumonia (AIP), transfusion related acute lung injury (TRALI)
Treatment dependent on underlying cause

Diffuse alveolar damage, abbreviated DAD, is a relatively common lung pathology that is grouped with the diffuse lung diseases and has several clinical correlates.



  • Abrupt hypoxemia with pulmonary infiltrates leading to epithelial cell and endothelial cell death not accompanied by cardiac failure.[1]

DAD is the histologic correlate of:

  • Acute respiratory distress syndrome (ARDS).
  • Acute interstitial pneumonia (AIP).
  • Transfusion related acute lung injury (TRALI).

The DDx is broad:[2]

  • Infection/sepsis.
  • Toxic (smoke, oxygen).
  • Drug (amiodarone, chemotherapy).
  • Trauma/shock.
  • Inflammatory.
  • Idiopathic.



  1. Exudative:
    • Hyaline membranes - key feature.
      • Debris (pink crap) lines the alveolar spaces.
  2. Proliferative:
    • Interstitial thickening.
    • Inflammation (lymphocytes).
    • Hobnailing of alveolar lining cells (type 2 pneumocyte hyperplasia[5]).
    • Edema (link pink crap in the alveoli).
    • Masson bodies in the airway.
    • Hyaline material (usu. focal) - key feature.
  3. Fibrotic:
    • Interstitial inflammation.
    • Fibrosis.




See also


  1. Mitchell, Richard; Kumar, Vinay; Fausto, Nelson; Abbas, Abul K.; Aster, Jon (2011). Pocket Companion to Robbins & Cotran Pathologic Basis of Disease (8th ed.). Elsevier Saunders. pp. 364. ISBN 978-1416054542.
  2. Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 91. ISBN 978-0781765275.
  3. Klatt, Edward C. (2006). Robbins and Cotran Atlas of Pathology (1st ed.). Saunders. pp. 103. ISBN 978-1416002741.
  4. 4.0 4.1 Castro, CY. (2006). "ARDS and diffuse alveolar damage: a pathologist's perspective.". Semin Thorac Cardiovasc Surg 18 (1): 13-9. doi:10.1053/j.semtcvs.2006.02.001. PMID 16766248.
  5. URL: http://d3jonline.tripod.com/20-Pulmonary_II/Pathology_of_Interstitial_Lung_Diseases.htm. Accessed on: 22 February 2012.