Hepatology (from derm?) Flashcards
Liver cirrhosis.
Chronic ‘end stage’ changed that may arise from a wide range of different causes of liver injury.
- usually repeated injury that has resulted in cell death, chronic inflammation and fibrosis.
– ultimate result = hepatic insufficiency.
- regenerative changes and attempts to increase functional mass but disrupted anatomical and functional aspects of the liver means this mass does not translate to effective hepatic function.
What characterises end-stage liver / cirrhosis.
Diffuse process that causes fibrosis and conversion of normal liver architecture into structurally abnormal lobules and seriously disturbed hepatic function.
Disturbance of hepatic vasculature - portal-central vascular connections mean increased resistance to blood flow and therefore portal hypertension.
Interspecific and intraspecific differences to liver response but all diffuse.
End stage liver / cirrhosis gross features.
Grossly abnormal.
Lobes irregular in shape.
Very nodular appearance.
Colour variation.
Changes are diffuse.
Disturbance in normal lobular architecture.
Fibrosis.
End stage liver / cirrhosis microscopic changes.
Extensive fibrosis - septums and bridging between portal and central areas.
- These can contain vascular channels that can allow blood to by-pass normal hepatocytes and sinusoids.
Fibrosis can surround and disturb interface between hepatocytes and blood so impaired exchange of substances between sinusoidal blood and hepatocytes, interfering w/ normal function.
Gall bladder hyperplasia in the dog.
Gall bladder mucosa often becomes hyperplastic, and sometime slightly cystic, w/ age - incidental finding in most cases.
Some dogs can get extreme hyperplastic change w/ lots of mucin production = gall bladder mucocele.
- highly thickened gall bladder wall, w/ gelatinous appearance due to mucin production
- can cause signs of biliary obstruction.
- can predispose to thrombosis of gall bladder wall – can lead to gall bladder rupture.
Hepatic nodular hyperplasia.
Common incidental finding in older dogs.
- occasionally seen in other spp.
1 or a few discrete nodular foci, either w/in hepatic parenchyma or on the surface.
May be up to several cm diameter.
Smooth surface to nodules.
Can be similar colour to surrounding parenchyma or different colour.
Increased hepatocyte number w/in nodules which are well-differentiated and arranged into modified lobules.
No clinical findings.
Need to be differentiated from something that is potentially more severe.
What types of primary tumour may arise in the liver?
Hepatocellular origin:
- hepatocellular adenoma or carcinoma.
Bile duct epithelium origin:
- cholangiocellular adenoma or carcinoma.
Mesenchymal origin e.g. endothelium, fibroblasts:
- e.g. haemangiosarcoma.
Hepatocellular adenoma.
Not particularly common.
Usually singular w/in liver - occasionally multiple.
Benign - grow by expansion - spherical.
Well-dermarcated.
Colour varies from similar to rest of liver parenchyma to pale brown/yellow colour.
Unless growth extensive, may not be able to differentiate from nodular hyperplasia.
- probably need histopathological exam to differentiate them from other disease.
Hepatocellular carcinoma.
Malignant.
Variable appearance.
- sometimes single, massive nodules resembling normal liver.
- sometimes multiple nodules scattered w/in liver – may represent intrahepatic spread of the tumour.
– or multiple tumours are arising simultaneously at different sites.
Can spread to local LNs and sometimes distant sites.
Cholangiocellular carcinoma.
Can be single or multiple.
Can arise from intrahepatic bile ducts or extrahepatic bile ducts.
Umbilicated appearance - central dip in the tumour.
Can spread intra-hepatically or extrahepatically e.g. local LNs, distant sites.
Tumour mass may start to obstruct the common bile duct, leading to biliary obstruction.
Neoplastic metastases to the liver.
Lymphoma - can appear nodular or diffuse (mottling or pallor) in the liver
Pancreatic tumours.
Gastric carcinoma.
Mammary tumours.
Haemangiosarcoma e.g. splenic.
Histiocytic.
