Hepato-Biliary Pathology Flashcards
What is the blood supply of the liver?
Receives dual blood supply from the hepatic artery and portal vein
Name three function of the liver
- Protein synthesis
- Metabolism of fat and carbohydrate
- Detoxification of drugs and toxins including alcohol
Name five different pathologies of the liver
- Liver failure
- Jaundice
- Intrahepatic bile duct obstruction
- Cirrhosis
- Tumours
Name a pathology of the gall bladder
Inflammation
Name a pathology of the extrahepatic bile ducts
Obstruction
What is liver failure
A complication of acute liver injury or chronic end-stage liver injury (i.e. cirrhosis)
Name two types of acute liver injury
Hepatitis and bile duct obstruction
Name three causes of hepatitis
Viruses, alcohol, drugs
How does bile duct obstruction cause acute liver injury?
Bile backs up into the liver which is damaging as it is toxic to it
Name different types of viral hepatitis and its pathology
A, B, C, E (D is closely related) and other viruses
Inflammation of liver cells -> liver cell damage and death of individual hepatocytes
What are the three possible outcomes for an acute liver injury?
Resolution = returns to normal (Hepatitis A & E)
Liver failure if severe damage to liver (Hepatitis A, B & E)
Progression to chronic hepatitis and cirrhosis (Hepatitis B & C)
What is the progression of alcoholic liver disease?
- Response of liver to excess alcohol
- Causes a fatty change – liver becomes fatty and fat accumulates in hepatocytes
- Alcoholic hepatitis
• Acute inflammation
• Liver cell death
• Liver failure - Progress to cirrhosis (with recurrent episodes of alcohol excess)
What is jaundice?
Cardinal sign of liver disease caused by increased circulating bilirubin caused by altered metabolism of bilirubin
What are the three stages of bilirubin metabolism?
- Pre-hepatic
- Hepatic
- Post-hepatic
What occurs in the pre-hepatic phase of bilirubin metabolism?
- Formed from breakdown of haemoglobin in spleen to form haem and globin
- Haem -> bilirubin
- Release of bilirubin into circulation
What occurs in the hepatic phase of bilirubin metabolism?
- Uptake of bilirubin by hepatocytes
- Conjugation of bilirubin in hepatocytes (making it more soluble to allow diffusion)
- Excretion of conjugated bilirubin into biliary system
What occurs in the post-hepatic phase of bilirubin metabolism?
- Transport of conjugated bilirubin in biliary system
- Breakdown of bilirubin conjugate in intestine
- Re-absorption of bilirubin ( entero-hepatic circulation of bilirubin)
What are three different types of causes of jaundice?
Pre-hepatic, hepatic and post-hepatic
Name a pre-hepatic cause of jaundice
Increased release of haemoglobin from red cells (haemolysis)
Name hepatic causes of jaundice
- Cholestasis (reduction in bile flow)
* Intra-hepatic bile duct obstruction
Name post-hepatic causes of jaundice
- Cholelithiasis (gallstones)
- Diseases of gall bladder
- Extra-hepatic duct obstruction
What is cholestasis?
Accumulation of bile within hepatocytes or bile canaliculi causing reduce bile flow
What are four causes of cholestasis?
- Viral hepatitis
- Alcoholic hepatitis
- Liver failure
- Drugs: therapeutic or recreational
Name three causes of intra-hepatic bile duct obstruction
- Primary biliary cholangitis
- Primary sclerosing cholangitis
- Tumours of liver
What is primary biliary cholangitis?
Organ specific auto-immune disease damaging the biliary ducts
- Mainly affects females
- Anti-mitochondrial auto-antibodies in serum
- Raised serum alkaline phosphatase
Describe the pathology of primary biliary cholangitis
- Granulomatous inflammation involving bile ducts
- Loss of intra-hepatic bile ducts
- Progression to cirrhosis
What is primary sclerosing cholangitis?
- Chronic inflammation and fibrous obliteration of bile ducts
- Loss of intra-hepatic bile ducts
- Progression to cirrhosis
- Increased risk of development of cholangiocarcinoma
What is hepatic cirrhosis?
End-stage chronic liver disease that occurs in response of liver to chronic injury
Name six different causes of hepatic cirrhosis
• Alcohol • Hepatitis B, C • Immune mediated liver disease - Autoimmune hepatitis - Primary biliary cholangitis • Metabolic disorders - Excess iron (primary haemochromatosis) - Excess copper (Wilson’s disease) • Obesity - Diabetes • Cryptogenic (unknown)
Describe the pathology of hepatic cirrhosis
- Diffuse process involving whole liver
- Loss of normal liver structure
- Replaced by nodules of hepatocytes and fibrous tissue
Name three possible complications of hepatic cirrhosis
• Altered liver function (liver failure)
• Abnormal blood flow (portal hypertension)
o Spleen enlarges
o Dilatation of porto-systemic venous anastomosis
• Increased risk of hepatocellular carcinoma
Name three different types of liver tumours
- Hepatocellular carcinoma
- Cholangiocarcinoma
- Metastatic tumours
What is Hepatocellular carcinoma?
Malignant tumour of hepatocytes
• Main risk factor: cirrhosis
What is cholangiocarcinoma?
Malignant tumour of bile duct epithelium
What are the two types of inflammation of the gall bladder?
Acute and chronic cholecystitis
What is acute cholecystitis?
Acute inflammation of gall bladder
What is a complication of acute cholecystitis?
Empyema – causes:
• Perforation of gall bladder
• Biliary peritonitis
Progression to chronic cholecystitis
What is chronic cholecystitis?
Chronic inflammation and fibrosis of gall bladder
Why is there RUQ pain in chronic cholecystitis?
Gallbladder is a muscular structure which contracts to release bile into the bile duct, so fibrosis impairs muscle and therefore abnormal function causing RUQ pain
Name four causes of bile duct obstruction
- Gall stones
- Bile duct tumour
- Benign stricture
- External compression (tumour i.e. tumour of pancreas can press on duct)
Name four effects of common bile duct obstruction
- Jaundice
- No bile excreted in duodenum
- Infection of bile proximal to obstruction (ascending cholangitis)
- Secondary bilary cirrhosis if obstruction prolonged
