Liver Pathology Flashcards
How much cardiac output goes to the liver?
25%
What structural unit of the liver contains the bile duct, portal vein, hepatic artery, and the nerves/lymphatic?
Portal triads
Clinical signs appear after _____% of the parenchyma injury
75
Biomarkers of liver function are??
Elevated - AST, ALT, LDH, alkaline phsophatase, gamma-glutamic transpeptidates
What are portals of entry of infectious agents to the liver?
Hematogenous
Retrograde through biliary and pancreatic ducts
Direct extension through the liver capsule
What are the mechanisms of liver injury?
Metabolic bioactivaion of chemicals
Stimulation of autoimmunity
Stimulation of apoptosis
Disruption of Ca homeostasis
Canalicular injury
Mitochondrial injury
What are causes of liver atrophy?
Increased catabolism
Decreased blood flow
Decreased bile flow
Pressure
Does the liver have regenerative capacity?
Yes
Stimulated by growth factors -> 60% of liver will regenerative within a week
What cells are responsible for liver regeneration?
Oval (stem) cells –> differentiate into hepatocytes or bile duct epithelium
What are the pre-requisites for liver regeneration?
Intact framework
Good blood supply
Patent bile ducts
How does hepatocellular regeneration appear histologically?
Nodular
What are the 3 general reponses of the liver to injury?
Regeneration of the parenchyma
Replacement by fibrosis
Biliary hyperplasia
What cells are responsible for liver fibrosis ?
Ito (stellate cells)
What causes milk spot liver in pigs?
Ascaris suis -> fibrosis due to parasitic migration
What do you call chronic injury and regeneration that results in hepatocellular nodular proliferation, fibrosis, and impaired blood or bile flow ??
Cirrhosis
T/F: in cirrhosis you have nodular regeneration and post-neurotic scarring making the liver increased in size
False
–> the liver is usually reduced in size
Capsular fibrosis in a horse. What do you do?
Nothing- incidental finding
Usually the end result of inflammation
Capsular fibrosis is AKA
Perihepatitis filamentosisa
Cattle..
Focal area of pale discolouration with attachment to the mesentery
Incidental lesions
Dog..
Enlarged liver
Multiple linear laceration of the hepatic capsule
Trauma
Liver with..
Pale irregular foci
Greenish black discolouration near the intestine
Emphysema
Liver autolysis -PM change
Yellow discolouration on surface of liver? What is this ?
Biliary inhibiton–> PM change
What are the random patterns of liver degeneration and necrosis
Single cell
Multifocal
Piecemeal
Etiology of multifocal liver necrosis with pale zones on the capsule of the liver
Bacterial
Viral
Parasitic
What pattern of necrosis is with a defined area like a lobule or acini?
Zonal
Every uniform pale discolouration
Centrilobular necrosis is commonly due to _________
Hypoxia
–> around the central vein
T/F: Mid zonal necrosis is a pattern that is rarely seen
True
Yellow fever can cause this
Periportal necrosis is often associated with what etiology?
Toxic
What do you call a liver that has necrosis of an entire lobule
Massive hepatic necrosis
Usually severe, but not always
What is the most common causes of massive hepatic necroissi in pigs?
Hepatosis dietetica –> associated with generation of free radicals and deficiency of vitE/Selenium
T/F: Cysts that have a thin wall.lined by a single layer of biliary epithelium may result in mortality due to liver or renal failure
False–>
Congenital biliary cysts usually incidental finding
What breeds are predisposed to congenital polycystic liver disease? What can these cysts caused?
Cair terriers,
West highland white terriers
Persian cat
Mortality due to liver or renal failure
A ventral hernia or diaphragmatic hernia are an example of what type of anomalies ?
Developmental -> displacement
Traumatic
What are the circulatory disturbances that can affect the liver?
Congestion Infarction (RARE) Thrombosis Congenital portosystemic shunt Telagiectasis
Right sided congestive heart failure leads to what disease of the liver?
Nutmeg liver
Caused by chronic passive congestion (of central vein)
Histology of a liver..
Congestion around central vein
Hepatocytes around portal area are normal
Midzonal fatty change
Congestion (nutmeg liver)
PM of large animal
Hepatomegaly
Ascities
Abnormal pain (history of)
Hepatic vein thrombosis
What are probable causes of hepatic vein thrombosis ?
Myeloproliferative disorders-> sluggish blood flow
Infection
Trauma
Neoplasia
Condition where blood bypasses the liver and drains into the posterior vena cava or the azygous vein
Portosystemic shunt
What are two manifestations that can be seen in congenital cages of portosystemic shunt in dog and cats?
Hepatic encephalopathy
Ascities
T/F: in portosystemic shunts, the liver can be very small?
True
Liver is deprived of primary perfusion and other growth factors
How can you differentiate acquired and congenital portosystemic shunts?
Acquired are due to chronic portal hypertension–> multiple thin walled and tortuous blood vessels
_______________ is the presence of focal areas in which sinusoids are dilated and filled with blood
Telangiectasis
Liver appears irregular, circumscribed, dark-red foci of cavernous ectasia of sinusoids
Telangiectasis
What is the significance of telangiectasis ?
Nothing clinically
Except ppl dont want to eat this cause it looks gross
Liver..
Pale discolouration
Round edges
Friable
Uniform Yellow discoloured
Tissue will float in water
Hepatic lipidosis
What is the pathogenesis of hepatic lipidosis ?
- Excessive entry of fat to liver
- Decreased oxidation of fatty acid
- Increased esterification of fatty acid to triglycerides
- Decreased apoprotein synthesis
- Impaired secretion of lipoprotein
Hepatocytes with marked hepatocellular vacuolation that pushes nucleus to peripheral of cell?
Hepatic lipidosis
What stain can you use to determine hepatic lipidosis ?
Oil red O
Osmium tetroxide
T/F: hepatic lipidosis is reversible
True -> in mild cases
Can lead to necrosis, fatty cysts, fat embolism, and liver rupture :(
When can you see physiological fatty liver?
Late pregnancy
Heavy lactation
Dietary excess
What can occur following excessive fat metabolism during peak lactation in cattle
Ketoisis
–> vacuolation in cells
When do we see bovine fatty liver syndrome?
Few days after parturition
Precipitated by event that cow goes off feed (eg retained placenta or metritis, ect)
Obese cat ..
Icterus
Hepatic failure followed by subsequent hepatic encephalopathy .. what could be the cause
Feline fatty liver syndrome
What breed of horses do we see hyperlipemia ?
Shetaland breed (unknown pathogenesis)
What endocrine disorders can lead to fatty liver
Diabetes -> lack of insulin-> no glucose uptake -> lipolysis-> increase fatty acid
Hypothyroidism
How is liver injury associated with hepatic lipidosis?
Hepatocyte injury-> decreased formation and/or export of lipoproteins by hepatocytes and decreased oxidation of fatty acids =>fatty degeneration
Glycogen accumulation can occur in what disease?
Diabetes
Hyperadrenocortisim
Glycogen storage disease
Excessive levels of _________ cause excessive swelling of hepatocytes leading to glycogen accumulation
Glucocorticoids
What is the DDX to a liver that is enlarged and pale due to swollen hepatocytes? How can these be differentiated?
Hepatic lipidosis
Steroid induced hepatopathy –> glycogen accumulation
PAS stain
_________________ usually occurs as a consequence to prolonged antigenic stimulation such as chronic infection
Hepatic amyloidosis
What breeds are genetically predisposed to hepatic amyloidosis?
Cat- Abyssinian and Siamese
Dog- Chinese shar-pei