Liver Pathology Flashcards
How much does the liver weight on average?
1500g, normally approx 4% of body weight
The liver has a dual blood supply, where do they come from?
Portal vein
Hepatic artery
What are the 6 types of cells of the liver?
- Hepatocytes - most metabolically active cell
- Bile ducts
- Blood vessels
- Endothelial cells
- Kupffer cells - resident macrophages of the liver
- Stellate cells - store vitamin A - when activated become myofibroblasts and lay down collagen
Describe the development of hepatocytes and where it occurs
Liver cells are born in zone 1 near the bile duct
Hepatocytes mature in zone 2
Retire when fully mature in zone 3, here the hepatocytes are the most metabolically active
Describe how and what happens when stellate cells of the liver get activated
Stellate cells are activated when the liver is damaged - hepatocyte villi is damaged/lost
Stellate cells are activated and lay down collagen/scar tissue and loss of fenestrae between endothelial cells
Define cirrhosis (4 things)
- whole liver involved
- fibrosis
- nodules of regneration hepatocytes
- distortion of liver vasculature architecture: both intra and extra hepatic shunting of blood e.g. gastro-oesophageal
How is cirrhosis classified?
- according to nodule size - micronodular or macronodular
AND
- According to aetiology
- alcohol/insulin resistance
- viral hepatitis etc.
What are the 3 main complications of liver cirrhosis?
- Portal hypertension
- Hepatic encephalopathy
- Liver cell cancer
Also, oesophageal varicies, splenomegaly due to chronic passive congestion
*Cirrhosis may be reversible
- What does this picture show?
- What is the most common cause?
- Oesophageal varicies - dilated tortuous vein
- Liver cirrhosis
What are the two main causes of acute hepatitis?
- Viruses
- Drugs
What does this slide show?
Acute hepatitis
- spotty necrosis - lots of little spots of inflammation, with lots of lymphocytes and macrophages
What are the 3 main causes of chronic hepatitis?
- Viral hepatitis
- Drugs
- Auto-immune
What does grade and stage of chronic hepatitis liver mean in histology?
- Grade = severity of inflammation
- Stage = severity of fibrosis
What does the picture show?
Interface hepatitis
Shows ‘piecemeal necrosis’
Shows the portal tract which has lost the definition as necrosis spreads across the limiting plate. T cell mediated destruction of hepatoyctes
What are the three stages of alcoholic liver disease?
- Fatty liver
- Alcoholic hepatitis
- Cirrhosis
What does this image show?
Fatty liver
Pale and yellow, suggesting lots of fat droplets
What are the histological features of alcoholic hepatitis?
- Ballooning (+/- Mallory Denk bodies)
- Apoptosis
- Pericellular fibrosis
- Mainly see in zone 3 of the liver - where hepatocytes are most metabolically active
What does this image show?
Alcoholic hepatitis
- Balloon cells
- Mallory Denk bodies
- Neutrophil polymorphs
- Pericellular fibrosis
What does this image show?
Liver cirrhosis
Pale due to fatty change, with associated nodules indicative of cirrhosis
What is NAFLD and NASH?
NAFLD - Non-alcoholic fatty liver disease
NASH - Non-alcoholic steatohepatitis
- Histologically looks like alcoholic liver disease
- Due to insulin resistance associated with a raised BMI and diabetes
Describe Primary Biliary cholangitis (PBC)
- Aetiology
- What it is
- Antibodies
- Previously known as primary biliary cirrhosis
- Bile duct loss assoacited with chronic inflammation, with granulomas
- More common in females then males
- Diagnostic test is detection of anti-mitochondrial antibodies
Describe Primary Sclerosing cholangitis
- Aetiology
- What is it
- Diagnostic test
- Periductal bile duct fibrosis leading to loss
- Associated with UC, and causes an increased risk of cholangiocarcinoma
- More common in males than females
- Diagnostic test is bile duct imaging
What is haemochromatosis?
- What is it?
- What gene is affected?
- Genetically determined increased gut iron absorption, leading to high levels of iron in the body and iron deposits in different organs. Parenchymal damage to organs occurs secondary to iron deposition - classic is in the pancreas leading to ‘bronzed diabetes’ as pancreas is damaged and change in skin colour due to iron deposition
- Gene on chromosome 6 - HFe
What does this image show?
Haemocrhomatosis
Liver full of brown pigments which are iron deposits, causes parenchymal damage in organs leading to reduced/loss of function
