fat necrosis A quick summary of the 6 types of necrosis

Q. I can’t seem to get the different types of necrosis straight (liquefactive, fibrinoid, etc.). Any help?

A. There are basically six distinct patterns of necrosis. It’s important to know about these, because they can give you a clue as to why the tissue died. We’ll go through these in bullet form to make it easy to compare.

Coagulative
  • See this in infarcts in any tissue (except brain)
  • Due to loss of blood
  • Gross: tissue is firm
  • Micro: Cell outlines are preserved (cells look ghostly), and everything looks red
Liquefactive
  • See this in infections and, for some unknown reason, in brain infarcts
  • Due to lots of neutrophils around releasing their toxic contents, “liquefying” the tissue
  • Gross: tissue is liquidy and creamy yellow (pus)
  • Micro: lots of neutrophils and cell debris
Caseous
  • See this in tuberculosis
  • Due to the body trying to wall off and kill the bug with macrophages
  • Gross: White, soft, cheesy-looking (“caseous”) material
  • Micro: fragmented cells and debris surrounded by a collar of lymphocytes and macrophages (granuloma)
Fat necrosis
  • See this in acute pancreatitis
  • Damaged cells release lipases, which split the triglyceride esters within fat cells
  • Gross: chalky, white areas from the combination of the newly-formed free fatty acids with calcium  (saponification)
  • Micro: shadowy outlines of dead fat cells (see image above); sometimes there is a bluish cast from the calcium deposits, which are basophilic
Fibrinoid necrosis
  • See this in immune reactions in vessels
  • Complexes of antigens and antibodies (immune complexes) combine with fibrin
  • Gross: changes too small to see grossly
  • Micro: vessel walls are thickened and pinkish-red (called “fibrinoid” because it looks like fibrin but has other stuff in there too
Gangrenous necrosis
  • See this when an entire limb loses blood supply and dies (usually the lower leg)
  • This isn’t really a different kind of necrosis, but people use the term clinically so it’s worth knowing about
  • Gross: skin looks black and dead; underlying tissue is in varying stages of decomposition
  • Micro: initially there is coagulative necrosis from the loss of blood supply (this stage is called “dry gangrene”); if bacterial infection is superimposed, there is liquefactive necrosis (this stage is called “wet gangrene”)
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41 Responses to A quick summary of the 6 types of necrosis

  1. Amelia says:

    Thanks! Made understanding the different types of necrosis and relevance of each, much easier!

  2. aaron says:

    I already love this site. Thank you so much for making it. I imagine this is an entry that tends to bring folks in, as it is so crucial in introducing Path. Quick, easy way to review what i am working on. Fantastic!

  3. baha`a says:

    it was really understandable

  4. Nazir Raisani says:

    I like this site, because it is much informative.

  5. Mirwais says:

    pathology student site is a very informative site for all medical students specifically for pathology students i like this site because i learn everyday new article about pathology.

  6. kabir says:

    Wonderful…………thanks Prof.

  7. Kristine says:

    You’re welcome! Glad it was useful.

  8. frank says:

    Brief and informative, i hope robbins can be written in this way too!

  9. Kristine says:

    Robbins is written MUCH better than this!

  10. andrew MD says:

    I like the site provide nice summary ..

  11. Aymen says:

    thank you for clear the type of necrosis .

  12. frank says:

    I have some “necrosis” that i dont know which category should be..
    1. the necrosis seen in solid tumor (“tumor” necrosis?)
    2. the necrosis seen in cat-scratch disease, it’s little bit caseous looking but more palisaded cells aside…I think caseous is more likely a gross term?

  13. Ehsan says:

    Thanks for the brief and clear explanations .

  14. summary is very nice

  15. Kristine says:

    Thanks! Glad you found it useful.

  16. Ron says:

    I have fatty necrosis, and this info was very informative….Thanks

  17. Ron says:

    Very informative for a person that has these symptoms and the disease.

  18. Kristine says:

    Great – Glad it helped! Hope you feel better.

  19. GOKUL says:

    cool, ws hlpful n esy to memorize

  20. awad says:

    so perfect summary that what I need >>>>>

  21. Lipane Suryakant Ramnath says:

    It is very excellent site to get advance knowledge of necrosis.

  22. Mohammed Abugu says:

    A very good summary that widen student’s memory 2 get more during reading. That is a very good work

  23. Tino says:

    Uuuhhh!!! So gud 2 b here. Itz brief n easier 4 d brain. . .provided av nt got liquefactive necrosis

  24. What ‘s an excellent site. 10x.

  25. Ehsan says:

    kiss, kiss, kiss! I love you pathology student! I really love you. Thanks a lot.

  26. AKHTAR HUSSAIN says:

    really so nice wounderfull side all informetion form this site so usenfull in daily practive hope i learn more form you if any training please i want to do
    thanks

  27. Arnold Audi says:

    makes quick and easy mastery

  28. natashah says:

    Thank u so much..very nice info

  29. d0my says:

    wonderful

  30. Cassidie says:

    Thanks for compiling this information. Very helpful!!!!

  31. Britt says:

    This was quite succinct and very effective. Thanks so much!

  32. Yami says:

    Very helpful

  33. purushothama says:

    thanks…………… a lot………………..

  34. inge says:

    Love ths staff

  35. Mussa Malanda says:

    Thanks much ,! I real love pathology

  36. Ruigy says:

    i love this site good work thnx

  37. Ruigy says:

    This site provides what pathology students want

  38. Lisa says:

    Oh, I forgot…my email is lgs1.flowerlady @yahoo.com. want to learn more about c-spine necrosis!!! Know and Orthopedic and /or Neurosurgeons and or Neuro or Ortho Oncologists or whatever specialty deals w/patients like me??

  39. Arvind says:

    why coagulative necrosis doesn’t occurs in brain,?

  40. Kristine says:

    Good question! I don’t know the answer. Robbins doesn’t explain it either – it says that in the brain, necrosis is of the liquefactive type “for unknown reasons.” I suspect there isn’t a good explanation of why this is so.

  41. hailemariam says:

    thanks for the brief explanation

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