Liver Pathology Flashcards
Portal triad
Portal vein
Hepatic artery
Bile duct
What are the 3 zones
Zone 1: Periportal
Zone 2: Mid zonal
Zone 3. Centrilobular (closet to terminal hepatic vein)
Patterns of liver disease
Cirrhosis ( end stage from chronic persistent damage to liver)
Portal hypertension (COmplication of cirrhosis etc)
Common Liver diseases
– Infectious disorders of the liver
– Drug and toxin induced liver injury
– Metabolic liver disease
– Haemochromatosis
Cirrhosis:
- typical liver anatomy findings
- Bridging fibrous septae (link portal tracts)
- Parenchymal nodules (proliferating hepatocytes encircled by fibrosis) micronodules (<3mm), macronodules (up to several centimetres)
- caused by fibrosis I bridging fibrosis (scarring between portal triads - Disruption of entire architecture
– Vascular architecture reorganised with shunts; PV & HA blood bypasses functional liver cells
– Progressive fibrosis (due to response of proliferation of hepatocytes - causes nodules AND loss of synthetic a detoxification functions of liver)
Portal Hypertension
- what is it
-Types
-consquences
elevated pressures within portal venous system
Types:
1. Prehepatic (obstructive thrombosis, often underlying thrombotic disorder)
- Posthepatic (severe R sided heart failure)
- Intrahepatic (cirrhosis)
- Consequences
– Ascites accumulation of fluid within abdomen
– Portosystemic shunts blood doesn’t go through liver. bypasses developing where systemic and portal circulation share capillary beds
– Congestive splenomegaly ↑ pressures a congestion
– Hepatic encephalopathy -> build up of toxic metabolites causes brain dysfunction consequence of blood bypassing liver. lose filtering stepa control of toxins
Symptoms/Signs of Portal hypertensio in setting of cirrhosis
- Heaptic encephalopathy (due to loss of normal detoxification functions of the liver)
- Ascites (portal hypertension can push fluid out of the reins into the
abdomen due to loss of oncotic pressure caused by low protein level due to loss of synthetic function & excess pressure in the veins 12 factors) - Malnurtrition
-Skin spider angiomata
-Esophageal varices (veins become dilated, varices can rupture I bleed due to portal hypertension, causes nematemesis (vomiting blood)
-Portal Vein (↑ pressure a dilation , may get reverse flow)
-Splenic Vein
-Splenomegaly (↑ pressure causes spleen to be enlarged (palpable
due to portal hypertension)
-Periumblicial caput medusae
-Hemorrhoids (due to portal hypertension ↑ flow through the hemorrhoidal veins)
-Testicualr atrophy
Infectious disorders
- Hepatitis A, B, C, D and E viruses
Cytomegalovirus
Epstein Barr Virus
Hep A
- Benign?
-Incubation period
-Cause of Chronic hep?
-Transmission/cause of infection
-symtpoms
-liver test results
Benign self-limited disease
Incubation period 2-6 weeks
Does not cause chronic hepatitis
- Substandard hygiene and sanitation
- Person to person, faecal-oral transmission
- Asymptomatic or mild febrile illness +/- jaundice
↑ in enzymes within the hepatocytes (ALTIAST)
↑ bilirubin
Hep B
- causes acute or chronic hep?
-Incubation period
-Transmission/cause of infection
-liver test results
Acute hepatitis with resolution OR if cant clear virus then Chronic hepatitis may lead to cirrhosis/cancers. Immune response to viral antigens expressed on infected hepatocytes leads to liver cell damage
- 4-26 weeks incubation
- Blood and body fluid borne
Increased bilirubin, ALT and AST
Flowchart of Hep B outcomes
Lecture Slide
Hep C
-transmission
-acute or chronic?
Infected blood / blood products eg blood transfusions, needle sharing
Acute infection usually undetected so Chronic disease occurs in majority
Drug and Toxin-Induced Liver Injury
CLASSIFICATION
ACTION
PATTERN OF INJURY
MOST COMMON DRUG/TOXIN CAUSING ACUTE LIVER FAILURE AND CHRONIC LIVER DISEASE
1.predictable hepatotoxins
- act in dose-dependent manner
- occur in most individuals
- unpredictable / idiosyncratic hepatotoxins
ACTION:
-directly cell toxic
-hepatic conversion to an active toxin
Pattern of injury
cholestasis, hepatocellular necrosis, fatty liver disease
fibrosis, granulomas, vascular lesions, neoplasms
Most common drug/toxin
acute liver failure - paracetamol in excessive dose
chronic liver disease - alcohol
Alcoholic Liver disease
-how does it chnage the liver
-causes what other complications
– changes in lipid metabolism
– decreased export of lipoproteins
– cell injury caused by reactive oxygen species (ROS) and cytokines
- hepatic steatosis (fatty change AKA fatty liver)
- ↑ lipid within hepatocytes,
causes liver dysfunction - alcoholic hepatitis
- cirrhosis (& hepatocellular carcinoma)
Alcoholic liver disease flowchart
Lecture Slide
Non-alcoholic fatty liver disease (NAFLD)
- assosicated with
Associated with metabolic syndrome, obesity, type 2 diabetes,
dyslipidaemia, hypertension
Haemochromatosis
- what is it
-cause
- Excessive accumulation of body iron that gets Deposited in liver and pancreas
Results from genetic defect causing excessive iron absorption
* Genetics: autosomal recessive
Cys282Tyr mutation in HFE gene, homozygous
* Transfusion transmitted iron overload
