Other nonneoplastic disease

Alveolar proteinosis

Last author update: 1 October 2011
Last staff update: 21 August 2020

Copyright: 2003-2023,, Inc.

PubMed search: alveolar proteinosis [title] pulmonary

Elliot Weisenberg, M.D.
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Cite this page: Weisenberg E. Alveolar proteinosis. website. Accessed November 28th, 2023.
Definition / general
  • Rare disease with accumulation of acellular surfactant presumedly due to impaired clearance, likely due to dysfunction of alveolar macrophages
  • Considered a response to alveolar injury, not a specific entity
  • Congenital (2% of cases), primary (idiopathic) or secondary forms
  • Congenital cases are usually due to mutation in surfactant protein or GM-CSF receptor genes
  • Secondary (most common), associated with silica dust, aluminum, fiberglass, chemicals, immunosuppression, leukemia / lymphoma, Nocardia, Mycobacteria and Aspergillosis
  • Usually adults (more common in smokers), also children
  • Sputum contains chunks of gelatinous material; no inflammation
  • Usually does NOT progress to chronic fibrosis
  • Xray: resembles pulmonary edema; diffuse pulmonary opacification
  • Whole lung lavage (also diagnostic)
Microscopic (histologic) description
  • Alveoli contain amorphous, eosinophilic and PAS+ material in lumina consisting of type II pneumocytes, lamellar bodies and necrotic alveolar macrophages
  • Variable fibrosis
  • Mild / no lymphocytic infiltration
Electron microscopy description
  • Exudate contains lamellar bodies, lipid particles and cellular debris
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