Necrosis is death of tissue or cells.
This is the most common form of necrosis and occurs in all organs. Cells retain their shape as cell proteins coagulate and metabolic activity stops
. Digestion by macrophages may cause the tissue to become soft. Histologically there is progressive loss of staining. The presence of necrotic material normally provokes an inflammatory response.
This occurs in the brain because of the lack of tissue architecture provided by substantial surrounding stroma.
Dead tissue lacks any structure, and is characterized by a white, soft or liquid â€˜cheesyâ€™ appearance. This is common in TB.
Necrosis with desiccation or putrefaction
In malignant hypertension necrosis of smooth muscle vessel walls allows seepage of plasma into the media and deposition of fibrin.
Direct trauma: release of extracellular fat produces an inflammatory response, fibrosis, and eventually in some cases a palpable mass.
Acute pancreatitis: fat is digested by pancreatic lipase to produce fatty acids that precipitate with calcium in the process of saponification.