Liver and Pancreas Pathology Flashcards
What is contained within the portal areas?
- Portal vein [nutrients from SI]
- Hepatic artery [oxygen]
- Bile ducts
Where do the radiating hepatocytes converge?
Central vein
What are the 3 hepatic zones?
- Periportal (centroacinar): around portal triads
- Midzonal
- Centrilobular (periacinar: bordering hepatic venules
What is the main congenital/developmental disorder of the liver? What other form exists?
Portosystemic shunt
- Congenital: shunting blood to vena cava, azygous or renal vein, usually single communication between vessels, easily surgically treatable
- Acquired: shunts 2* to fibrosis of the liver in older animals, multiple thin walled shunts -> more difficult to treat
What is the limiting plate?
Area around portal triad - used to decide whether inflammation is contained within portal tract or has spread to hepatocytes
How may portosystemic shunt be diagnosed microscopically?
Biopsy -> microscope -> If portal vein is missing then shunt is present
Give 5 other congenital/developmental disorders of the liver
- Congenital cysts (mostly biliary, mainly in cats [also dogs and pigs] may be multiple, no sig)
- Displacements (congenital or acquired, eg. diaphragmatic hernia)
- Tension lipidosis (focal subcapsular fatty change where liver attaches to diaphragm, may be due to local chronic ischamiea)
- Capsular fibrosis (common older horses due to migrating parasites or foci of non-septic peritonitis)
- Telangiectasis (normal, foci of sinusoidal dilatation esp cats and cattle)
How does passive venous congestion affect the liver grossly and microscopically?
- Enlarged with rounded borders
- Oozes blood on cut surface
- NUTMEG liver (enhanced lobular pattern due to areas of fatty change and congestion)
- Microscopically
> hepatic venules and sinunois engorged
> periacinar areas congested and hepatocytes atrophied
> periportal areas fatty change -> pale colour
Would heart failure persist long enough for the entire liver to degenerate?
No
Give 4 common disorders of of pigmentation
- Melanin (congenital melanosis in calves and lambs, no sig)
- Haemosiderin due to chronic passive venous congestion (nutmeg liver, of potential significance)
- Bile (obstructive jaundice, sig)
- Lipofiscin or ceroid (brown, comes with aging, no sig)
What is hydropic change? Is it common? Is it revesible?
> A vacuolar hepatopathy
Influx of H20 -> cells -> swelling
- Common
- Reversible
What may cause hydropic change?
- hypoxia
- mild toxic damage
- metabolic stress `
What pathologic change may appear similar to hydropic change? What may cause this?
Glycogen accumulation (gylcogenosis) - Hyperadrenocorticsim (Cushings) may cause this
What would be seen with glycogen accumulation? Is this reversible?
Multifocal/diffuse swelling and vacuolation in hepatocytes
- Enlarged pale liver (Severe cases; steroid hepatopathy)
> reversible!
When is lipidosis (fatty liver) seen (4)?
1 - Obesity and starvation (esp cats)
2 - ^ energy demand (pregnancy, lactation, starvation) -> mobilisation of fat stores
3 - Disease (eg. diabetes mellitis, ketosis, pregnancy toxaemia)
4 - Abnormal hepatocyte function (prevents fatty acids complexing protein -> LDL; leading to accumulation)
Is lipidosis reversible?
NO
How common are lysosomal storage diseases?
Rare
What are the causes of lysosomal storage diseases?
- inherited deficiency of lysosomal enzymes -> neuro disease
- macrophages containing stored material accumulate at MULTIPLE sites (LNs, liver, CNS) Liver easiest to biopsy [may be diagnosed at PM]
How common is amyloidosis?
Uncommon
What is the pathophysiology of amyloidosis? What forms exist?
- substance deposited under endothelium and basement membrane of variety of tissues (renal glomeruli, islets of Langerhans, liver)
- 1, 2, endocrine associated
How does amyloidosis appear grossly and mmicrscopically?
- Gross: pale, enlarged and friable liver
- Microscopic: Homogenous acidophilic material
- shows green birefringence when stained with congo red
- results in displacement and atrophy of hepatocytes
What 4 reasons may necrosis occour?
- Ischaemia
- Toxinc damage
- Nutritional deficiencies
- Microbial infection
What are the 3 patterns of necrosis? What pathologies are these associated with?
- Random: EHV-1, salmonella
- Zonal: Ichaemia, toxic damage
- Massive: Hepatosis dietetica
What is hepatosis dietetica?
Vit D and selenium deficiency disorder in pigs
What are the 4 types of fibrosis of the liver?
- Periacinar fibrosis (surrounding central vein, CHF and passive congestion)
- Biliary fibrosis (accompanying inflammation centred on the portal triads (usually infection or inflammation from gut/bile duct)
- Post-necrotic scarring following massive necrosis (rarely seen as usually -> death)
- Cirrhosis = end stage liver disease, hard to ID inciting cause but also irrelevent (extensive fibrotic lesions, +- concurrent nodular regeneration and hyperplasia)
What are the 3 forms of inflammation of the liver?
- Hepatitis (liver parenchyma often cuased by infection)
- Cholangitis (bile ducts, may be immune mediated [esp cats] or associated with infection [eg. salmonellosis in calves]
- Cholangiohepatitis (both)
What does acute hepatitis usually involve? What succeeds it and how does this progress?
- Necrosis
- Succeded by inflammation
- progression =
> complete resolution by regeneration (massive regenerative capacity of liver)
> repair by fibrosis/scarring
> encapsulation by abscessation
> persistence by granulomatous disease
What 3 viruses may cause hepatitis?
- Adenoviruses (canine infection hepatitis)
- Herpesviruses ( EHV-1, infectious bovine rhinotracheitis, feline viral rhinotracheitis, Aujeskys disease
- Coronaviruses (feline infectious peritonitis)
Which animals are commonly affected by viral hepatic disease?
Young and unvaccinated
Which animals does canine infectious hepatits affect?
Young dogs
What type of virus causes infectious canine hepatitis?
Adenovirus
How is infectious canine hepatitis shed? Is this long or short term shedding?
Urine - long term