During necrosis, nuclear changes appear in one of the 3 patterns

During necrosis, nuclear changes appear in one of the 3 patterns, all due to nonspecific breakdown of DNA

Karyolysis(Dissolution) is complete dissolution of the chromatin of a dying cell due to enzymatic degradation by endonucleases.

Pyknosis(Condensation) is irreversible condensation of chromatin in the nucleus of the cell undergoing necrosis or apoptosis characterized by nuclear shrinkage and increased basophilia.

Karyorrhexis(Fragmentation) is destructive fragmentation of the nucleus of a dying cell whereby its chromatin is disturbed irregularly throughout the cytoplasm.