Liver Necrosis

Causes

• severe metabolic disturbances [as seen in degenerative pathology link?]
• toxic substances [link?]
• nutritional deficiencies
• action of micro-organisms

Histological patterns

• Liver cell necrosis has been classified on an anatomic basis with reference to the distribution of the lesion

Random foci (focal)

• microscopic foci of necrosis not related to any particular part of the liver lobule
• can be due to a variety of insults
  • systemic viral, bacterial,and parasitic infections
  • result of bacteria being absorbed from the gut
• examples
  • Equine herpes virus infection
    • in aborted foetuses
  • Salmonellosis
    • in calves
  • Toxoplasmosis (miliary)
    • in dogs and cats

Zonal necrosis

• necrosis occurring mainly in a part of the lobule and further subdivided according to whether the lesions are situated centrally, peripherally, or in the mid-zone of the lobule
• due to anoxia

Periacinar (centrilobular)

• most common
• main reason is because the hepatocytes in this zone are furthest away from the incoming blood supply
  • therefore less oxygenated and relatively anoxic
• reported to contain the greatest number of enzymes responsible for metabolising sunstances to more toxic metabolites capable of killing the hepatocytes
• hypoxic states and toxic substances predominate in this type of necrosis
• some viral conditions cause this necrosis
  • eg Infectious Canine Hepatitis
• poisons
  • eg carbon tetrachloride

Midzonal

• rare
• in pigs with alfatoxicosis
• 'Yellow Fever' in man

Periportal (centroacinar)

• rare
• eg phosphorous poisoning

Massive necrosis

• necrosis of large areas of liver cells comprising many lobules (complete acinus or several acini) and sometimes involving almost the whole organ
• some cases of ICH infection or carbon tetrachloride poisoning, the severity of the injury replacing the zonal pattern

Subacute cytolytic necrosis

• a condition in the dog
• aetiology is entirely unknown
• Clinical
  • acute abdominal pain
  • collapse
  • invariably jaundice
• Gross
  • Liver is normal or reduced in size
• Microscopically
  • severe necrosis

Hepatosis dietica

• similar condition to subacute cytolytic necrosis
• occurs in rapidly growing pigs
• related to diet
  • fed on large quantities of grain concentrates
  • poor quality or low quantity protein supplements
• Cause
  • nutritional deficiencies of selenium and Vitamin E, and probably amino acids
  • triggering mechanism is environmental stress

Test yourself with the Liver Pathology Flashcards

Liver Pathology Flashcards