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
