Paraffinoma (Lipoid Pneumonia)



Paraffinoma (Lipoid Pneumonia)







Key Facts


Terminology



  • Synonyms



    • Cholesterol pneumonia, lipoid pneumonia, golden pneumonia


  • Definition: Type of pneumonia that could be secondary to aspiration; can be classified as



    • Endogenous


    • Exogenous


Etiology/Pathogenesis



  • Exogenous



    • Aspiration of oily substances


    • Mineral oil


    • Vegetable oil


    • Petroleum jelly


    • Oil mists


    • Some radiographic contrast media


  • Endogenous



    • Result of pulmonary obstruction or gastroesophageal reflux


    • May result as a breakdown of cell membrane or lipoprotein secretions


Clinical Issues



  • Rare; may be seen in bedridden patients


  • Can occur in any age group, children or elderly


Microscopic Pathology



  • Proliferation of foamy histiocytes


  • Cholesterol cleft granulomas


  • Foreign body giant cell reaction


  • Fat droplets in interstitium


  • Inflammatory reaction may be minimal






Low-power view of lipoid pneumonia shows the characteristic “Swiss cheese” appearance. Note the number of cystic spaces image and focal areas of inflammation image.






With this closer view of lipoid pneumonia, note the presence of several multinucleated giant cells image. The normal lung architecture is lost, and the inflammatory reaction is minimal.


TERMINOLOGY


Synonyms



  • Cholesterol pneumonia, lipoid pneumonia, golden pneumonia, exogenous/endogenous lipoid pneumonia


Definitions



  • Type of pneumonia secondary to aspiration; can be classified as



    • Endogenous


    • Exogenous


ETIOLOGY/PATHOGENESIS


Etiology



  • Exogenous



    • Aspiration of oily substances



      • Mineral oil


      • Vegetable oil


      • Petroleum jelly


      • Oil mists


      • Some radiographic contrast media


  • Endogenous



    • Result of pulmonary obstruction or gastroesophageal reflux


    • May result from breakdown of cell membrane or lipoprotein secretions


CLINICAL ISSUES


Epidemiology



  • Incidence



    • Rare; may be seen in bedridden patients


  • Age



    • Can occur in any age group, children or elderly


  • Gender



    • No gender predilection


Presentation



  • Cough


  • Chest pain


  • Dyspnea


  • Fever


Treatment



  • In cases of endogenous lipoid pneumonia, dealing with cause of obstruction may be beneficial


  • In cases of exogenous lipoid pneumonia, identification and stopping of probable cause is crucial


  • Antibiotics may be necessary


Prognosis



  • Depends on origin, but in some cases, endogenous lipoid pneumonia can be fatal


IMAGE FINDINGS


Radiographic Findings



  • May be a mixture of interstitial and alveolar pattern


MACROSCOPIC FEATURES


General Features



  • Soft and yellowish consolidated areas


MICROSCOPIC PATHOLOGY


Histologic Features



  • Proliferation of foamy histiocytes



    • Intraalveolar


    • Interstitial


  • Cholesterol cleft granulomas


  • Foreign body giant cell reaction



    • Around fat droplets in exogenous pneumonia


    • May be absent in cases of endogenous pneumonia


  • Fat droplets in interstitium



  • Inflammatory reaction may be minimal


Cytologic Features



  • Fat droplets in interstitium


  • Positive staining in frozen tissue for oil red O

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Jul 9, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Paraffinoma (Lipoid Pneumonia)

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