Chapter 4 - Necrosis Flashcards
6 types of Necrosis
Coagulative
Liquefative
Caseous
Fat
Fibrinoid
Gangrenous
Coagulative Necrosis is seen in…
Ischemia/infarcts (except brain)
Coagulative Necrosis: histology
Preserved cellular architecture, but nuclei disappear;
Eosinophilia; red/pink color
Liquefactive Necrosis is seen in…
Brain infarcts and Bacterial abscesses
Liquefactive Necrosis is due to…
Neutrophils release of lysosomal enzymes
Liquefactive Necrosis: histology
Early: cellular debris and macrophages
Late: cystic spaces and cavitation (brain)
Neutrophils and cell debris seen with bacterial infection
Caseous Necrosis is seen in…
TB, Nocardia and systemic fungi (eg, Histoplasma capsulatum)
Caseous Necrosis: histology
Fragmented cells and debris surrounded by lymphocytes and macrophages
Fat Necrosis is seen in…
Acute pancreatitis (saponification of peripancreatic fat)
Trauma
Pancreatic Fat necrosis: mechanism
Release of lipase → breaks down triglycerides → fatty acids bind calcium → saponification (chalky-white appearance)
Fat Necrosis: histology
Outlines of dead fat cells without peripheral nuclei; saponification of fat appears dark blue on H&E stain
Fibrinoid Necrosis is seen in…
Immune vascular reactions (eg, PAN)
Nonimmune vascular reactions (eg, hypertensive emergency, preeclampsia)
Fibrinoid Necrosis is due to…
Immune complex deposition and/or plasma protein (eg, fibrin) leakage from damaged vessel
Fibrinoid Necrosis: histology
Vessel walls are thick and pink
Gangrenous Necrosis is seen in…
Distal extremity and GI tract, after chronic ischemia
Dry Gangrenous Necrosis is due to…
Ischemia
Wet Gangrenous Necrosis is due to…
Superinfection
Dry Gangrenous Necrosis: histology
Coagulative
Wet Gangrenous Necrosis: histology
Liquefactive superimposed on coagulative
