Liver Flashcards
What congenital conditions may be found in the liver?
- Aplasia/ supernumerary lobes
- Intrahepatic cysts
- Portosystemic shunts
Describe this lesion
The entire liver parenchyma has been disrupted by disseminated fluid-filled, soft cystic structures. Areas of tissue which are not cystic show multifocal areas of haemorrhage or yellow discolouration.
Chronic disseminated severe polycystic hepatopathy
Genetic in persians
What is the difference between an intra and extrahepatic shunt?
Which structures do they arise from?
Intra - within the liver - Persistence of ductus venosus
Extra - within and outside of the liver - a direct connection between HPV and vena cava/ azygous veins
Intrahepatic shunt
Persistent ductus venosus
Extrahepatic shunt
Describe the appearance of the liver of an animal which has a porto-systemic shunt.
- Microhepatia
- Small hepatocytes
- Small or absent portal veins in triads
- More arterioles in triads
Describe this lesion
The normal anatomy of the thorax and abdomen of this cat has been severely disturbed, with the small intestine and other abdominal viscera being displaced cranially, presumably through the diaphragm.
Acute severe diffuse traumatic diaphragmatic herniation of the gastro-intestinal tract.
Outline the expected sequelae of hepatic torsion
Venous occlusion
Ischemia
Necrosis
In what situations may a liver be prone to rupture?
Trauma
Amyloidosis
Lipidosis
ie increased friability of parenchyma
Which of the zones of hepatic lobules is most vunerable to passive hyperaemia?
Zone 3 - closest to central vein
Which type of passive congestionmay be seen as an agonal change?
Acute
Describe this lesion.
Name a possible sequelae
The parenchyma of the liver shows disseminated round black lesions with non-affected tissue showing either redenning or multifocally shown to be pale tan. The surface of the liver is diffusely roughened.
Chronic disseminated severe fibrosing passive hyperaemia of the liver
Sequelae: acquired porto-systemic shunt
Chronic fibrosis of the liver leading to reduced and inadequate liver function.
Cirrhosis
What is shown here?
Possible cause?
Dilation of non-functioning tortuous vessels between the portal vein and caudal vena cava.
Due to hepatic fibrosis/ cirrhosis
Acute passive congestion due to heart failure
Teleangiectasis
Dilation of functional vessels - sinusoids in the liver
Describe this lesion
Multifocal to coelescing black irregularly shaped (3cm across) lesions can be seen on the surface of this liver and also present on the cut surface.
Acute multifocal to coelescing severe teleangiectasis of hepatic sinusoids
Irregular blood-filled cystic spaces in the liver parenchyma.
Cause?
Peliosis hepatis
Cause: focal hepatocyte necrosis
The most metabolically active hepatocytes are found where in hepatic ascini?
Zone 3 - centrolobular
Histologically how do degenerating hepatocytes appear?
Why?
- Cloudy
- Swollen
- Rounded cells
ie Hydropic degeneration
Right of the image - hydropic degeneration of hepatocytes due to influx of Na+ and H2O
Atrophy of the liver due to external pressure - neoplasia, dilated viscera etc
In which four situations can hepatic lipidosis occur?
- Nutritional - obesity/ fat rich diet
- XS FFA released from adipose due -ve energy balance
- Hypoxic lipidosis - decreased beta oxidation of fatty
- Toxic lipidosis due to decreased apoproteins
Describe this lesion
The surface and deep tissue is focally extensively pale tan, with about 80% of the hepatic tissue being affected. The tissue itself is extremely friable when touched.
Diffuse moderate subacute hepatic lipidosis
Pale yellow, greasy tissue seen with hepatic lipidosis
Vacuolation and peripherisation of hepatocyte nuclei seen with hepatic lipidosis
Which type of stain is used for visualisation of lipids in hepatocytes?
Oil red orange
What three conditions can animals be prediposed to hepatic lipidosis?
Hyperlipidaemia - DM, pancreatitis, hypothyroidism, hyperadrenocorticism, nutritional
- equine hyperlipidaemia, feline idiopathic hepatic lipidosis
Ketosis - starvation, DM, pregnancy, lactation
- Sheep; pregnancy toxaemia “twin lamb disease”
Hypoglycaemia and fatty liver syndrome in small dog breeds
How can ketosis lead to hepatic lipidosis
Increased demand for gluconeogenesis or glucose, impaired utilisation of glucose
Excessive breakdown of adipose tissue
Increased free fatty acids
Why does hyperadrenocorticism lead to hepatic lipidosis?
Action of glucocorticoids leads to:
- Decreased lipogenesis
- Increased lipolysis of adipose tissue
- Increased catabolism of skeletal muscle protein
- Increased gluconeogenesis in the liver (↑ glycogen stores)
What does this PAS stained histological slide show?
Increased glycogen storage within hepatocytes
Feathery degeneration of glycogen filled cytoplasm of hepatocytes
What can cause increased glycogen storage in hepatocytes?
Diabetes mellitus
Glycogen storage disease
Steroid induced (exogenous/endogenous)
What is amyloid?
Pathological proteinaceous substance deposited between cells (in space of Dissé and sinusoids)
AA vs SAA
Describe this lesion
Diffusely affected. The surface appears rough and yellow in colour and shows multifocal areas of haemorrhage and the liver has rounded edges suggesting enlargement.
Chronic diffuse severe necrotising hepatic amyloidosis
Amyloid depositations within sinusoids
Multifocal to coelescing moderate congenital melanosis
Increased iron uptake in birds and humans can lead to an accumulation of this substance.
What stain would be used for visualisation?
Haemosiderin - Haemochromatosis
Prussian blue
What situations can lead to accumulation of haemosiderin in hepatocytes?
- Increased iron intake
- Erythrolysis
Intoxication with which three plant types can lead to photosensitisation?
How does this work?
- St. John`s wort (Hypericum perforatum)
- buckwheat (Fagopyrum spp.)
- spring parsley (Cymopterus watsoni)
Metabolism of iron porphyrins in the liver leads to build up of photosensitive uroporphyrins = photodermatitis
Photodermatitis secondary to intoxication with iron porphyrins
Focal hepatic necrosis can be caused what aetiological agents
Herpes virus
Toxo
Disseminated pathogen
Multifocal to coelescing coagulative necrosis (preservation of tissue of architecture)
Tyzzers - Clostridium piliforme
Focally irregular area of hypereosinophilic hepatocytes with nuclear and cytoplasmic fragmentation.
Rabbit haemorrhagic disease