Lipoid pneumonia

Lipoid pneumonia is a form of pneumonia associated with oily or lipid components within the pneumonitis component.

This can either result from

Most patients are asymptomatic and often discovered incidentally. 

Lipid-laden macrophages are often seen in histological samples following transthoracic needle biopsy. With exogenous forms, inhaled lipid content (e.g. from aspiration) is phagocytosed by macrophages which fill alveoli. A subsequent acute +/- chronic pneumonitis results.

Macroscopically the affected regions often have a yellowish or golden hue, which is thought to be produced by the liberation of lipid material from alveolar pneumocytes secondary to the inflammatory reaction. 

  • aspiration risk
    • neuromuscular disorders
    • esophageal abnormalities
    • cleft palate

The endogenous type can be seen in association with lung cancer 2.

Case reports are emerging in patients who use e-cigarettes (vaping) 12.

A fibrotic component can develop in chronic cases.

Other possible complications include:

  • superinfection by non-tuberculous mycobacteria
  • respiratory insufficiency
  • cor-pulmonale
  • hypercalcemia
  • can be variable 3
  • radiological spectrum with consolidation to an irregular mass-like lesion to a reticulonodular pattern
  • characteristically show low attenuation within the consolidated areas (low attenuation consolidation) of ~ -100 HU reflecting a fat content (at times the attenuation value may be less i.e. around -30 HU and higher than that of subcutaneous fat 10)
  • consolidation may have a predilection for the dependent portions of the lungs 3
  • associated ossific foci may be present within the affected region
  • a crazy paving pattern may also be seen

Not part of routine evaluation. Signal characteristics may reflect fat/paraffin content. usually:

  • T1: high to intermediate signal 7
  • T2: low to intermediate signal 7

Serial radiographs showing stability may be enough in asymptomatic patients with no background history. A biopsy can be performed in some of the cases to ensure the benign nature of the lesion, especially if changes are lipid-poor and imaging features persistent.

The mainstay of management in exogenous types is control and cessation of offending agent(s).

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Article information

rID: 9967
System: Chest
Synonyms or Alternate Spellings:
  • Lipoid pneumonias
  • Lipid pneumonia
  • Lipid pneumonias
  • Lipoid pneumonia - general

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Cases and figures

  •  Case 1
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  • Case 2
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  • Case 3: acute exogenous lipoid pneumonia
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  • Case 4: complicated by NTB infection
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