Pathology of the Liver and Pancreas Flashcards
What are the characteristics of a normal liver lobe?
2mm
Pentagon
Bounded by portal tracts
Hepatocytes converge on central vein
Why is the liver poorly oxygenated?
Portal veins contain mostly nutrients and is mixed eith hepatic artery on way to central vein
How does bile flow relate to blood flow in the liver?
They flow in opposite directions. Bile is produced in the canaliculi and flows away from the central vein, towards the bile duct
What are the zones in the liver lobule and how well is each one oxygenated?
- Centrilobular - Least oxygenated
- Midzonal
- Periportal - Most oxygenated
What usually causes passive venous congestion resulting in nutmeg liver?
Right sided congestive heart failure
What is the gross and microscopic appearance of venous congestion?
G - Enlarged rounded borders, blood from cut surface and nutmeg liver
M - Congested venules and sinusoids, dark red hepatocytes in centrilobular zone, pale red hepatocytes in periportal zone
How do congenital and acquired PSS differ anatomically?
C - Single shunt to larger BV
A - Multiple thin walled shunt
What pigments can result in liver pathology and how do they come about?
Melanin - Congenital
Haemosiderin - Venous congestion
Bile - Icterus
Lipfuscin/cerioid - Ageing
What is the gross and microscopic appearance of vacuolar hepatopathy?
G - Enlarged pale liver
M - Multifocal-diffuse swelling and vacuolation of hepatocytes
Outline the pathogenesis of fatty liver…
Disease/NEB > abnormal hepatocyte function > decreased FA complexing > decreased low density lipoproteins
Describe the gross and microscopic appearance of amyloidosis of the liver
G - Pale orange, enlarged fribale
M - Homogenous, acidophilic material, stains green in Congo red
What can cause hepatic necrosis?
Ischaemia
Toxic damage
Nutritional deficiencies
Microbial infection
What usually results in the liver from acute ingestion of toxins?
Decreased synthesis and increased consumption of clotting factors –> haemorrhage
Give 4 examples of toxins that damage the liver
Ragwort
Copper
Sulphonamides
Paracetamol in cats
What are the three types of liver inflammation and what parts of the liver do they affect?
Hepatitis - liver parenchyma
Cholangitis - bile ducts
Cholangiohepatitis - parenchyma and bile ducts
What is the usual cause of hepatitis?
Infectious
What can cause cholangitis?
Immune-mediated
Infection
Acute hepatitis is followed by inflammation. If the animal survives how might it then progress?
Complete resolution by regeneration
Repair by fibrosis and scarring
Encapsulation by abscessation
Persistence by granulomatous disease
What types of viruses can cause hepatitis?
Adenovirus
Herpesvirus
Coronavirus
What animals do viral hepatitis generally occur in?
Young
Unvaccinated
What is the pathology of infectious canine hepatitis?
Widespread haemorrhages
Enlarged, reddened and haemorrhagic LNs
Inflamm in the eye with opaque corneas
Give 4 examples of herpesviruses
Equine viral rhinopneumonitis
IBR
Refline viral rhinopnumonitis
Aujezsky’s
What is the pathology of herpesvirus?
Aborted foetus/neonates
Pinpoint foci of hepatic necrosis
Necrosis to lungs, kidneys, spleen and adrenals
What is the pathology of FIP?
Pyogranulomatous lesions in multiple organs esp liver
What routes can the liver become infected with bacteria?
Direct - adjacent tissues
Haematogenous - portal vein from GIT, hepatic artery with bateraemia, umbilicus
Abscesses - umbilicus, rumenitis
What does Fusobaterium necrophorum cause?
Bacillary necrosis in cattle/sheep
What does Clostridium novyi type B cause?
Black’s disease/infectious necrotis hepatitis in sheep
What does Clostridium haemolyticum cause?
Bacillary haemogloburia in cattle/sheep
What does Clostridium piliforme cause?
Tyzzer’s disease in lab rodents, neonatal foals and immunocompromised SA
What species in Lepto most common in?
Dogs
What species is most affected by Salmonellosis? What is the principle species?
Calves
S. dublin
How does the aetiology of bacillary necrosis differ in adults and calves?
A - enters circ following rumenitis
C - enters via umbilicus
What is the pathology of bacillary haemoglobinuria?
Anaemia, icterus, haemogloburia
Focally extensive hepatic necrosis
Haemoglobin staining of kidneys
How is Clostridum piliforme identified?
Wheat sheaf appearance of colonies in silver stain
What are the clinical signs of leptospirosis?
Haemolytic anaemia
Haemorrhages
Icterus
Which parasites is responsible for milk spot liver?
Ascaris suum
Which parasite can damage the liver during migration in horses?
Strongyles
What infectious causes can inflam the gallbladder?
Salmonella
Infectious canine hepatitis
What is the consequences of gall bladder rupturing?
Bile peritonitis
Which animal is liver hyperplasia common in?
Dogs
Which species is primary liver neoplasia common in?
Dogs and cats
Which cells can form a primary liver tumour?
Hepatocytes
Bilary epithelium
What are the characteristics of haemangiosarcomas of the liver?
Primary or secondary
Secondary from spleen or RA
Prevalent in large breed
Name 4 tumours likely to metastasise to the liver…
Melanoma
Carcinoma
Sarcoma
Lymphoma
Which breeds/species are most likely to suffer from pancreatic hypoplasia?
GSD
Calves
What are the clinical signs of pancreatic hypoplasia?
Diarrhoea
Weight loss despite increased appetite
Potbellied
Lack of abdominal fat
What are the clinical signs of acute pancreatitis?
Shock
Increased lipase and amylase
Outline the pathophysiology of chronic pancreatitis…
Repeated bouts of acute pancreatitis –> Fibrosis and atrophy –> EPI
Which animals are affected by pancreatic hyperplasia?
Older cats and dogs
Is pancreatic hyper and hypoplasia clinically significant?
Hyper - no
Hypo - yes, cause EPI
What type of neoplasia is most common in SA pancreas?
Carcinoma
Where do pancreatic carcinomas metastasis to?
Liver Peritoneum LNs Spleen Adrenals
