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.
- 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
- 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
- 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)
- 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
- 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
- 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”)
- Dottie W said Sorry, I am on 10mg of prednisone and I got the book, BOOP: You’re The Boss. Excellent read by...
- Dottie W said This is in response to Sharon T and Mary. I think people respond to this monster in varying degrees....
- Chris Roecker said DCM??? I was thinking it would be Takotsubo cardiomyopathy (broken heart syndrome).
- Kristine said The blasts stay in their own category. You want to make sure you count them separately from any othe...
- Kristine said Hi Kristin – Thanks for your interest in the course! Each session should take about 10 minutes...
- Monica said I have been doing some practice runs with CBCs and calculating absolute counts. The ones I have been...
- Kristin Briscoe said Just trying to plan my studying efficiently- looks like I have forgotten a lot of neuro! Just wonder...
- Patty Timberwolf said Another disease it has been said he could have had was Camurati–Engelmann disease (CED)it also calle...
- ravi s said Thank you
- ravi s said Thank you
- Kristine said Hi Hannah – the course is more of a medical-school-level course. I have had comments that it w...
- Hannah said I was wondering if the course was more suited for USMLE step 1, 2, or path residency level. Will sig...