Paper I
Question
Types of necrosis
Answer
- Coagulative necrosis: Tissue architecture preserved for days; classic in ischaemic infarcts of most solid organs (e.g., heart, kidney, spleen)
- Liquefactive necrosis: Tissue converts to a liquid, viscous mass; seen in bacterial/fungal infections (pus formation) and cerebral infarcts (unique among infarcts)
- Caseous necrosis: Combination of coagulative and liquefactive features, producing a friable, cheese-like, granular appearance; characteristic of tuberculosis
- Fat necrosis: Focal areas of fat destruction, typically from release of activated pancreatic lipases (acute pancreatitis) or direct trauma to fat-rich tissue (e.g., breast)
- Fibrinoid necrosis: Deposition of immune complexes and fibrin in vessel walls, seen in immune-mediated vasculitis and malignant hypertension
- Gangrenous necrosis: Not a distinct pattern but a clinical term applied to a limb (usually lower) that has lost its blood supply and undergone coagulative necrosis (dry gangrene), which may be complicated by superimposed bacterial infection producing liquefactive changes (wet gangrene)