Which of the following are characteristic of necrosis: Increase in nuclear-cytoplasmic ratio, Karyolysis (dissolution of the nucleus), Pyknosis (condensation of the nucleus), Karyohexis (fragmentation of the nucleus), or Somatic mutation?

Characteristic Changes of Necrosis

Karyolysis, pyknosis, and karyorrhexis are all characteristic nuclear changes of necrosis, while increased nuclear-cytoplasmic ratio and somatic mutation are not features of necrotic cell death.

True/False Answers:

1. Increase in nuclear-cytoplasmic ratio: FALSE

   • This is not a characteristic feature of necrosis 1
   • Necrosis typically involves cytoplasmic swelling (oncosis), which would actually decrease the nuclear-cytoplasmic ratio 2, 3

2. Karyolysis: TRUE

   • Karyolysis (dissolution of the nucleus) is a definitive characteristic of necrosis 1
   • This represents complete dissolution of chromatin by DNase activity 3
   • Karyolysis is the predominant nuclear change in oncotic necrosis (cell death with swelling) 3
   • The process involves progressive nuclear fading and eventual disappearance 4

3. Pyknosis: TRUE

   • Pyknosis (nuclear condensation with shrinkage) is characteristic of necrosis 1
   • Necrotic pyknosis involves peculiar chromatin condensation into small, irregular patches 1
   • This differs morphologically and biochemically from apoptotic pyknosis, where chromatin remains attached to the nuclear envelope 5
   • In necrotic pyknosis, chromatin detaches from the nuclear envelope before the envelope collapses onto chromatin 5

4. Karyorrhexis: TRUE

   • Karyorrhexis (nuclear fragmentation) is a characteristic feature of necrosis 1
   • This involves fragmentation of the pyknotic nucleus into multiple discrete fragments 3
   • Karyorrhexis occurs during the most marked chemical changes in disintegrating tissue 4

5. Somatic mutation: FALSE

   • Somatic mutations are genetic alterations that occur in living cells, not dead cells 1
   • These mutations occur during cell life and proliferation, particularly in cancer development 1
   • Necrosis represents cell death with loss of membrane integrity and cellular disintegration 1, 6

Key Distinguishing Features of Necrosis:

• Cytoplasmic changes: Generalized swelling (oncosis), translucent cytoplasm, organelle swelling 1, 2
• Nuclear changes: Karyolysis, pyknosis with irregular chromatin patches, and karyorrhexis 1, 3
• Membrane integrity: Irreversible plasma membrane permeabilization and disruption 6, 2
• Mitochondrial changes: Swelling with flocculent densities and possible calcification 2