Learning Radiology xray montage

Lipoid Pneumonia

  • Exogenous accumulation of fat in the lung most often from mineral oil:

  • Older people who are constipated, have a swallowing disorder 2° neurologic disease

  • In infants with feeding difficulties

  • In the past, could be from oily nose drops

  • Accumulation of fat in the lung may also occur from endogenous sources such as fat embolism, alveolar proteinosis lipid storage diseases

  • Animal fatty acids (like fat embolus) produces hemorrhagic bronchopneumonia

  • Mineral oil produces a giant cell foreign body reaction

  • Starts as an alveolar infiltrate

  • Moves to thicken interstitial septa, then

  • Into macrophages enlarging lymphatics

  • Finally produces a fibrosing reaction


  • Usually lower lobes with predilection for the right

  • Alveolar consolidation, may be well-circumscribed

  • May present as a peripheral mass with fuzzy or distinct margins simulating BrCa

  • Fat attenuation on CT

lipoid pneumonia

Lipoid Pneumonia. Low-attention masses in right lung (white arrows), both with fat density measurements represent lipoid pneumonia.

Lipoid Pneumonia

Lipoid Pneumonia. Same case as above showing chest radiograph on right with area of consolidation in lower lobe (black circle) which contains fat on CT (white circle).


  • Usually asymptomatic


  • Best method of DX is direct Bx

  • Fat-laden macrophages are non-specific since they can be found in sputum of normals as well