Liver Pathology Flashcards
What is the basic structure of the liver?
The hepatic lobule; a hexagonal structure with the hepatic vein in the centre, and the portal tracts at the periphery.
What are the functions of the liver?
Metabolism
- Involved in glycolysis, glycogen storage, synthesis of essential molecule
- Involved in drug metabolism
Protein synthesis
- Involved in amino acid synthesis
- Makes all circulating proteins (except gamma globulins)
Storage
- Glycogen, vitamin A, D, B12
- Vitamin K, folate, iron, copper
Hormone metabolism
- Activates vitamin D
Bile synthesis
- 600-1000ml a day
Immune function
- Kupffer cells (macrophages)
Name and describe some benign tumours of the liver
Haemangioma
- Most common benign lesion
- No symptoms or treatment
Hepatic adenoma
- Associated with the OCP
- Present with abdominal pain/intraperitoneal bleeding
- Treat with resection if symptomatic, large or unresponsive to stopping the OCP
Name and describe some malignant tumours of the liver
Metastases
- Most common malignant lesion of the liver
- Usually from GI/breast/lung
- Usually multiple
Hepatocellular carcinoma
- Caused by cirrhosis, HepB or C, NAFLD
- Secrete alpha-fetoprotein
Haemangiosarcoma
Hepatoblastoma
- Liver malignancy of childhood
- Primitive cells
Cholangiocarcinoma
- Carcinoma arising from the bile ducts
- 10% of all liver malignancies
- Can be intra or extra hepatic
- Carry a poor prognosis
- Caused by PSC, parasitic liver disease
What is cirrhosis?
A diffuse abnormality of the liver architecture which interferes with function and blood flow. It is characterised with the following:
- Fibrosis
- Hepatocyte necrosis
- Nodules of regenerating hepatocytes
- Disruption of liver architecture
What are the main causes of cirrhosis?
- Alcoholic liver disease
- Non-alcoholic fatty liver disease
- Chronic viral hepatitis
- Autoimmune hepatitis
- Biliary causes
- Genetic causes
What is the modified Child’s Pugh score?
A score to indicate prognosis in cirrhosis. It scores based on ascites, encephalopathy, bilirubin levels, albumin levels and prothrombin time. The higher the score, the lower the expected survival.
What is portal hypertension? At what point does the circulation begin to change?
It is increased pressure in the portal system, which is usually secondary to :
- Increased resistance vascular resistance
- Hyperdynamic circulation
- Sodium retention and plasma volume expansion
When portal pressure is raised above 10-12mmHg, collateral vessels begin to form to create varices at:
- Gastro-oesophageal junction
- Rectum
- Left renal vein
- Diaphragm
- Retroperitoneum
- Anterior abdominal wall
What can cause portal hypertension?
Pre-hepatic:
- Portal vein thrombosis
Hepatic:
- Pre-sinusoidal: PBC, schistosomiasis
- Sinusoidal: cirrhosis
- Post-sinusoidal: veno-occlusive disease
Post-hepatic:
- Budd-Chiari syndrome (blockage of the hepatic vein)
What is the progression of alcoholic liver disease?
Hepatic steatosis
- Large, pale, yellow, greasy liver
- Accumulation of fat droplets
- Fully reversible if alcohol stopped
Alcoholic hepatitis
- Large, fibrotic liver
- Hepatocyte ballooning and necrosis
- Mallory Denk bodies
- Can be seen acutely
Alcoholic cirrhosis
- Yellow-tan, fatty liver
- Micronodular cirrhosis
Describe non-alcoholic fatty liver disease
It is hepatic steatosis in non-alcoholics, and is increasingly common. Risk factors include obesity and insulin resistance.
- Simple steatosis: relatively benign
- NASH: can progress to cirrhosis
Describe autoimmune hepatitis
It commonly comes with other autoimmune disease (SLE, coeliac, thyroiditis) and predominately affects females and is associated with HLA-DR3. There are two types:
- Type 1: anti-SMA, ANA
- Type 2: anti-LKM
It is treated with immune suppression
Describe the biliary causes of cirrhosis
Primary biliary cholangitis (PBC)
- Autoimmune inflammation of intrahepatic ducts
- Females 10x at risk, peak at 40-50 years
- Raised ALP, cholesterol, anti-mitochondrial antibodies in 90%
- US: no dilatation
- Histology: granulomas
- Presents with pruritus and abdominal discomfort
- Treat with ursodeoxycholic acid
Primary sclerosing cholangitis (PSC)
- Inflammation of extrahepatic and intrahepatic ducts
- Multiple stricture formation
- Males at higher risk, 40-50 years peak
- Associated with IBD (especially ulcerative colitis)
- Raised ALP, and p-ANCA
- US: duct dilatation
- ERCP: beading of bile ducts
- Risk of cholangiocarcinoma
What genetic diseases can cause cirrhosis?
- Haemochromatosis
- Wilson’s disease
- Alpha-1-antitrypsin deficiency
What is haemochromatosis? What is the associated epidemiology? What is the pathophysiology and histology? What are the associated clinical features? What are the investigations and treatment principles?
Increased iron deposition in tissues, and it peaks at 40-50 years
It is an autosomally recessive disease, involving a mutated HFE gene causing increased iron absorption in the gut. A Prussian blue stain can visualise the iron deposits.
Clinically, there is a classic bronzing of the skin, diabetes, hepatomegaly, cardiomyopathy, hypogonadism, pseudogout.
Bloods will show a high iron, and ferritin, and a reduced total iron binding capacity. Treatment is with venesection and Desferrioxamine.
