.
**Coagulative necrosis** generally occurs due to an infarct (lack of blood flow from an obstruction causing ischemia) and can occur in all the cells of the body except the brain. The heart, kidney, adrenal glands, or spleen are good examples of coagulative necrosis. Cells that undergo coagulative neRead more
**Coagulative necrosis** generally occurs due to an infarct (lack of blood flow from an obstruction causing ischemia) and can occur in all the cells of the body except the brain. The heart, kidney, adrenal glands, or spleen are good examples of coagulative necrosis. Cells that undergo coagulative necrosis can become dry, hard, and white.
On the other hand, **caseous necrosis** is a unique form of cell death in which the tissue maintains a cheese-like appearance. It is also a distinctive form of coagulative necrosis. The dead tissue appears as a soft and white proteinaceous dead cell mass. Frequently, caseous necrosis is encountered in the foci of tuberculosis infections.
See less
Morphology of necrotic cell: A) Cytoplasmic changes: -Increased eosinophilia – Due to denatured proteins and loss of cytoplasmic RNA. -Glassy homogenous appearance – loss of glycogen particles. -Moth eaten appearance of cytoplasm – enzymatic digestion of cytoplasmic organelles. -Whorled phospholipidRead more
Morphology of necrotic cell:
A) Cytoplasmic changes:
-Increased eosinophilia – Due to denatured proteins and loss of cytoplasmic RNA.
-Glassy homogenous appearance – loss of glycogen particles.
-Moth eaten appearance of cytoplasm – enzymatic digestion of cytoplasmic organelles.
-Whorled phospholipid masses derived from damaged cell membranes – myelin figures.
-Calcifications – fatty acids derived from phospholipid masses.
B) Electron microscopic findings: Necrotic cells are characterized by-
-Discontinuities in plasma and organellar membrane.
-Swollen mitochondria with large amorphous densities.
-Intracytoplasmic myelin figures.
-Aggregates of fluffy material representing denatured proteins.
C) Nuclear changes: Due to the non-specific breakdown of DNA, 3 patterns are identified-
See less-Karyolysis – fading of basophilia of chromatin due to enzymatic degradation of DNA by endonucleases.
-Pyknosis – nuclear shrinkage & increased basophilia.
-Karyorrhexis – pyknotic nucleus undergoes fragmentation.