Definition:-
Necrosis is the series of morphological changes that follow cell death in lethally injured of living cells.
· In which cellular membrane fall apart and cellular enzymes leak out and ultimately digest the cell.
· Necrosis is caused by various agent such as hypoxia, chemical & physical agents ,microbial agent, immunological injury etc.
Types:- Types of necrosis based on etiological &morphological appearance.
1) Coagulative Necrosis :-
* This is the most common type of necrosis caused by irrversible cell injury.
* It’s mainly caused by sudden stop of blood flow and less often from bacterial & chemical agents.
* The organ commonly affected area are heart, kidney & spleen.
* Denaturation of all protein and its own lysosomal enzymes are also denatured.
* Later dineted by Leukocytes. For eg. - All infarcts expect brain.
2)Liquefactive Necrosis :-
* Tissue get converted into liquid viscous mass.
*It’s due to ischemic injury and fungal or bacterial infection.
*Hydrolytic enzymes caused to tissue degradation & material become ; semi fluid material (creamy yellow pus ) for eg.- Brain infarets, & abscess cavity.
3)Caseous Necrosis :-
* This type of Necrosis is found in the centre of foci of tuberculosis infections.
*It’s combine feature of both coagulative & liquefactive necrosis.
*It’s resemble like dry cheese (yellow white colour) soft & granular for eg.-Tuberculosis
4) Fat Necrosis:-
* Fat necrosis mainly occurs in fat rich anatomic location in the body like breast.
*Fat become fat distruction ; calcified to produce chalky white area.
*Calcium deposition around the inflammatory border for eg. – Acute pancreatitis
5) Fibrinoid Necrosis :-
Deposition of fibrin like material
Commonly seen in immune complex mediated vasculitis for eg.- Auto immune disease, Vasculitis peptic ulcer.
Reference-
Robbins basic pathology chapter 1 cellular ageing 9th edition
Textbook of Pathology chapter 3 cellular adaptation and cell injury 8th edition
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