Types of necrosis II (So nice we hit it twice)

gangrenous necrosis

Not a specific pattern of cell death, but a term that denotes a type of necrosis that develops at the distal aspect of extremities or dependent portion of organs

wet and dry

what are the two forms of gangrenous necrosis

wet gangrene

Necrotic tissue invaded by saprophytic or putrefactive bacteria leads to what?

abundant fluid and warmth

wet gangrene occurs in tissue with abundant what?

with gas producing bacteria (Clostridium)

gas gangrene forms when?

aspiration pneumonia

bacterial infections

torsion, volvulus, incarceration, intussusception

What causes gangrenous necrosis in the lung?

In the mammary tissue?

In the intestine?

presence of both liquefactive and coagulative necrosis

liquefactive

What is characteristic of wet gangrene microscopically?

Which type of necrosis is more prominent?

wet gangrene

what type of necrosis

swollen soft tissue, wet, dark red/green, putrid odor, sharp line of demarcation, emphysematous

describe a wet gangrene's gross appearance

hydrogen sulfide + iron = iron sulfide

Hydrogen sulfide gas (smell)

What would turn a wet gangrenous lesion black?

Why would they smell so bad?

dry gangrene

what type of gangrene results from a local tissue hypoxia or ischemia? (often extremities)

infarction, mechanical constriction, frostbite, fescue foot

what can cause dry gangrene?

coagulative necrosis

What does dry gangrene look like microscopically?

dry leathery texture, cool, shriveled

describe a dry gangrene grossly

wet gangrene is an emergency and leads to septicemia/toxemia/shock,

dry gangrene doesn't lead to toxemia, and dead tissue normally sloughs and heals

compare the end outcomes of wet vs dry gangrene

ulceration

Not a specific pattern of cell death, but a term that denotes a type of necrosis of epithelium

ulcer = full thickness

erosion = partial epithelial loss

What si the difference between an ulcer and an erosion?

trauma, infectious agents, ischemia

What can cause ulceration?

thinning/loss of mucosa; plus or minus crust/exudate

describe the gross apearance of an ulceration

regeneration, fibrosis/scarring, adaptation

What is the ultimate outcome of an ulcer?

fat necrosis

Not a specific pattern of cell death, but a term that denotes focal areas of fat degeneration and death

nutritional, enzymatic, traumatic, idiopathic

what are the 4 causes of fat necrosis?

polyunsaturated fatty acids, vitamin E

Nutritional fat necrosis: Diets high in __________________ / low in _____________

pancreatic lipases leaking into the body,

fatty acids, glycerol, soap

Enzymatic fat necrosis is caused by _______________________.

These split triglycerides into _________ and _______.

The first of which can combine with calcium, sodium, and potassium to make _________

blunt trauma or chronic pressure

Traumatic fat necrosis is caused by ________ or _____________

clear, pale eosinophilic, basophilic

normal adipocytes stain ________

Necrotic adipocytes stain ____________ and have _______ mineral soap deposits

true

true/false: whatever stimulates fat necrosis can stimule a robust immune response leading to fat-filled macrophages (and some neutrophils)

saponification

"soap formation"

firm, nodular, yellow/white, granular, soapy/chalky fat

describe fat necrosis grossly

fibrinoid necrosis

Not a specific pattern of cell death, but a term that denotes a

microscopic change seen in blood vessels, where the vessel wall is bright pink, homogenous, and amorphous

Leakage of plasma proteins into the vessel wall

what causes fibrinoid necrosis?

bright pink, homogenous, amorphous

what do the vessel walls look like again? In fibrinoid necrosis...

fibrinoid

What type of necrosis?

true... duh

True/false: the appearance of a necrosis depends on the type of necrosis, tissue involved, cause of cell death and time elapsed

type, location and number of cells affected. Rate at which they are affected

what does the outcome of necrosis depend on?

regeneration, recruitment of inflammatory response (liquefaction, encapsulation, sequestration), replacement by scarring (mineralization), adaptation (hyperplasia, hypertrophy, metaplasia, atrophy)

What are some possible outcomes of necrosis?

4 general things (with specifics in parenthesis)

gangrenous

type of necrosis

caseous

type of necrosis

coagulative (see outline of cells)

Type of necrosis

hepatic coagulative necrosis

give me a morphological diagnosis. Heres a zoomed out pi and a closer view of the lesion

liquefactive

type of necrosis

cerebral liquefactive necrosis OR cerebral abscess

morphological diagnosis?

fat necrosis

type of necrosis?

renal coagulative necrosis

morphological diagnosis