Histopathology 19 - Liver pathology Flashcards
(50 cards)
why does the liver not tend to get affected by ischaemic disease?
Dual Blood Supply
Hepatic portal vein
Hepatic artery
what is different about liver endothelial cells?
do NOT sit on basement membrane
endothelium is discontinuous - no tight junctions
What is the function of stellate cells in the liver?
store vitamin A
activated → myofibroblasts → collagen → scarring in liver disease
What does the portal triad consist of?
hepatic artery (branch)
portal vein (branch)
bile duct
What is the ring around the portal triad called?
ring of collagen around the portal tract - limiting plate (boundary between hepatocytes and portal tract)
How does blood flow through the hepatic cells?
from portal tract → diffuse through sinusoids → central vein
‘They begin life in zone 1, grow up in zone 2 and retire in zone 3’ (zone 3 has most metabolically active enzymes)
What happens to the liver cell architecture when there is liver injury?
Kupffer cells activated (typical inflammatory response)
IMPORTANT: BM-type collagens secreted into the space of Disse by activated stellate cells
Hepatocytes lose microvilli
Endothelial cells stick together so blood cannot → hepatocytes
Where are the stellate cells located?
between endothelial cells and hepatocytes - space of Disse
Blood goes through spaces between endothelial cells → contact with hepatocytes
What is spotty necrosis on histology indicative of?
acute hepatitis
What pathology is suggested by portal inflammation and lymphocytes WITHIN vs CROSSING the limiting plate?
within - chronic hepatitis
crossing - interface (piecemeal) hepatitis
What does liver fibrosis lead to?
fibrosis in between portal tract and central vein
→ intrahepatic shunting → blood will go straight from the portal tract to the central vein without being filtered
What happens to blood flow in liver cirrhosis?
Distortion of liver vascular architecture: intra- and extra-hepatic shunting of blood
Normally, blood from intestines → filtered through liver → comes out via hepatic vein
intrahepatic shunting - blood passes through liver but no contact with hepatocytes due to scarring → unfiltered and toxic
extrahepatic shunting
blood never reaches liver → backlogs into sites of porto-systemic anastomosis (e.g. GEJ)
What are satellite nodules in the liver indicative of?
cancer secondary to liver cirrhosis
How can nodule size be used to understand the aetiology of liver cirrhosis?
Micronodular -aw alcoholism
Macronodular - aw viral infections
What are the complications of liver cirrhosis?
Portal hypertension
Hepatic encephalopathy
Liver cell cancer
What does cirrhosis massively increase the risk of?
HCC
What are the 3 histological patterns in alcoholic liver disease?
Fatty liver
Alcoholic hepatitis
Cirrhosis
NOTE: they may co-exist, they are not distinct entities
What are some causes of fatty changes in the liver?
alcohol and insulin resistance main causes - also in Kwashikor
NOTE: anyone that drinks in excess will undergo some fatty change but this is reversible
What are the histological features of alcoholic hepatitis?
Ballooning (w/wo Mallory Denk bodies) - MDB are pink deposits within cells - Mallory hyaline
Fat
Pericellular fibrosis
Which zone of the liver is most affected by alcoholic hepatitis?
zone 3 - most metabolically active
by the time blood has gone past zones 1 and 2 and reached zone 3, it is relatively hypoxic → vulnerable to damage
Which part of alcohol is toxic to the liver?
alcohol NOT toxic, acetaldehyde IS toxic
What is the cause of non alcoholic fatty liver disease?
insulin resistance associated with raised BMI and diabetes
What is primary biliary cholangitis?
bile duct loss associated with chronic inflammation (with granulomas)
Which antibody is associated with primary biliary cholangitis ?
anti-mitochondrial antibodies (AMA)
