pathology of liver and pancreas Flashcards
Describe the make up of a liver lobule
about 2mm in diameter
polyhedron bounded by portal areas which contain a branch of the portal vein, hepatic artery, and a bile duct. hepatocytes are arranged in converging radiating cords which centre on the central vein. Sinusoids and bile canaliculi in between
What are the three hepatic zones?
periportal around portal triads
midzonal
centrilobular
What is a PSS?
congenital - blood shunts from the portal vein into the vena cava by passing the liver
Acquired - secondary to fibrosis - multiple thin walled shunts
Most kind of congenital cysts are ____ cysts. Cats > dogs
biliary
Tension lipidosis looks like ___ and occurs due to ____
focal areas of subcapsular change
local ischaemia
Which species commonly get capsular fibrosis tags in old age?
Horses
often due to parasitic migration or peritonitis
what is telangiectasis?
foci of sinusoidal dilatation
Passive venous congestion of the liver is usually associated with ____
right sided heart failure
What does passive venous congestion look like grossly?
Enlarged liver with rounded borders. Oozes blood on cut surface
enhanced lobular pattern - nutmeg liver
What does passive venous congestion look like microscopically?
periacinar areas congested atrophy of hepatocytes
periportal areas - fatty change
Which species get congenital melanosis of the liver?
calves and lambs
What is the cause of haemosiderin pigmentation of the liver?
chronic passive venous congestion
what kind of pigmentation do you get with obstructive jaundice
bile pigmentation
What is the cause of lipofuscein pigmentation?
ageing
What are the common causes of vacuolar hepatopathies?
hypoxia, mild toxic damage, metabolic stress
What accumulates in the liver in hyperadrenocorticism?
glycogen
what does steroid hepatopathy look like grossly?
enlarged pale liver
How does fatty liver come about?
dietary: obesity or starvation
Increased energy demand: pregnancy, lactation, starvation
disease: DM, ketosis, regnancy toxaemia
abnormal hepatocyte function (prevents fatty acids complexing with proteins to form low density lipoproteins)
What is the pathogenesis of lysosomal storage diseases?
inherited deficiencies of lysosomal enzymes
How do you diagnose lysosomal storage diseases?
liver biopsy or post mortem.
Will see macrophages with stored material in liver, spleen, LNs)
Where does amyloidosis occur?
under the endothelium and basement membrane of organs - glomeruli, islets of langerhans in pancreas, liver.
What does the liver look like grossly in amyloidosis?
pale friable liver prone to rupture
what does amyloidosis look like microscopically?
acidophilic material - green on congo red
What causes periacinar fibrosis?
chronic passive congestion
How does biliary fibrosis occur?
chronic inflammation centred on the portal triads
What does cirrhosis look like?
extensive fibrotic lesions
seen in end stage liver, may have concurrent nodular regeneration
Which species suffers from immune mediated cholangitis?
immune mediated
Salmonellosis in calves may lead to what change in the liver?
Cholangitis
What are the 4 potential sequelae to hepatitis if the animal survives?
Complete resolution by regeneration
repair by fibrosis and scarring
Encapsulation by abscessation
Persistence- granulomatous disease
Three families of virus that cause hepatitis?
Adenovirus
Herpes virus
Coronavirus (FIP)
What age of animals are mainly affected by canine infectious hepatitis?
What kind of virus is it?
Young dogs
adenovirus type 1
how is canine infectious hepatitis shed?
in the urine - long term
What cell types does canine infectious hepatitis have tropism for?
endothelium - widespread haemorrhages particularly on serosal surfaces
hepatocytes
what might the lymph nodes and tonsils look like in canine infectious hepatitis cases?
reddened and enlarged. sometimes haemorrhagic
what ocular changes might you see in recovering canine infectious hepatitis patients?
immune mediated uveitis
corneal opacity
4 examples of herpesviruses
Equine herpes
IBR
feline viral rhinopneumonitis
aujezsky’s disease
What might you suspect if there are pinpoint foci of necrosis on the liver?
herpesvirus
necrosis also in the lungs, kidneys, spleen
What is the pathogenesis of FIP?
enteric coronavirus that has mutated leading to systemic vasculitis and effusions.
Pyogranulomatous lesions in organs
What are the two forms of FIP?
dry - granulomatous
wet - effusive
What are the three routes of bacterial infection in the liver?
Direct extension from adjacent tissues
Haematogenous spread
Abscessation e.g. from rumenitis in cows
What organism causes bacillary necrosis?
fusobacterium necrophorum
What are the 2 main causes of bacillary necrosis?
calves - umbilicus
cattle - rumenitis
What does bacillary necrosis look like grossly?
multiple pale foci of necrosis
may develop into abscesses
What does bacillary necrosis look like microscopically?
coagulative necrosis with bacteria at the periphery
