Pathology of the liver and pacreas Flashcards Preview

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Flashcards in Pathology of the liver and pacreas Deck (76)
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1
Q

Portosystemic shunt

A

congenital or acquired

portal blood bypasses the liver

2
Q

Portosystemic shunt - congenital

A

shunting into vena cava, azygos or renal vein

usually a single communication between the vessels

3
Q

portosystemic shunt - acquired

A

shunts secondary to fibrosis in older animals

multiple thin-walled shunts

4
Q

Congenital cysts

A

most are biliary

can be multiple

5
Q

displacements

A

congenital or acquired

6
Q

tension lipidosis

A

focal areas of subcapsular fatty change
may relate to local ischaemia
usually the tip where it touches the diaphram

7
Q

capsular fibrosis

A

fibrous tags are common on the surface of the liver in older horses

8
Q

telangiectasis

A

foci of sinusoidal dilatation

cats + cattle

9
Q

Circulatory disorders - passive venous congestion - presentation

A

usually associated with right-sided heart failure acute or chronic

10
Q

Circulatory disorders - passive venous congestion - gross pathology

A

liver enlarged with rounded borders and oozes blood on cut surface
enhanced lobular pattern (‘nutmeg liver’)

11
Q

Circulatory disorders - passive venous congestion - microscopy

A

hepatic venules and sinusoids engorged
periacinar areas are congested with atrophy of hepatocytes (red colour)
periportal areas undergo fatty change (pale colour)

12
Q

common pigments

A

melanin
haemosiderin
bile
liofuscin

13
Q

vacuolar hepatopathies

A

degenerative
hydropic change is common, non-specific and reversible
glycogen accumulation (glycogenosis) occurs in
hyperadrenocorticalism
multifocal to diffuse swelling and vacuolation of hepatocytes
enlarged pale liver in severe cases

14
Q

vacuolar hepatopathies - causes

A

hypoxia, mild toxic damage and metabolic stress

15
Q

lipidosis - causes

A

dietary factors: obesity and starvation
incr energy demand
disease (e.g. diabetes mellitus, ketosis and pregnancy toxaemia)
abnormal hepatocyte function that prevents fatty acids
complexing with proteins to form low density lipoproteins

16
Q

Abnormal deposits and accumulations - lysosomal storage diseases

A

inherited deficiencies of lysosomal enzymes – neuro disease
macrophages containing stored material accumulate at multiple sites (liver, lymph nodes, central nervous system)
diagnosed by liver biopsy or post mortem examination

17
Q

Abnormal deposits and accumulations - amyloidosis

A

substance deposited under the endothelium + basement membranes of a variety of tissues - renal glomeruli, islets of Langerhans in the pancreas + liver
primary, secondary or endocrine-associated

18
Q

amyloidosis - gross appearance

A

Liver pale, enlarged and friable – prone to rupture

19
Q

amyloidosis - microscopic appearance

A

homogeneous acidophilic material that shows green birefringence when stained with Congo red

20
Q

Necrosis of the liver - causes

A

ischaemia
toxic damage
nutritional deficiencies
microbial infection

21
Q

necrosis - patterns

A

Random: e.g. EHV-1 or salmonellosis
Zonal: e.g. ischaemia or toxic damage
Massive: e.g. hepatosis dietetica

22
Q

Fibrosis of the liver - Patterns of fibrosis

A

Periacinar fibrosis
Biliary fibrosis
Post-necrotic scarring
Cirrhosis

23
Q

Periacinar fibrosis

A

fibrosis surrounds central vein

chronic passive congestion

24
Q

Biliary fibrosis

A

accompanying inflammation

centred on the portal triads

25
Q

Post-necrotic scarring

A

following massive necrosis

26
Q

cirrhosis

A

extensive fibrotic lesions
end stage liver
may be concurrent nodular regeneration

27
Q

hepatitis - define

A

Inflammation of the liver parenchyma

ften caused by infection

28
Q

cholangitis - define

A

Inflammation of the bile ducts

may be immune-mediated or associated with infection (e.g. salmonellosis in calves)

29
Q

cholangiohepatitis - define

A

Inflammation of parenchyma and bile ducts

30
Q

progression of hepatitis

A
necrosis, succeeded by inflammation 
If the animal survives then progression is: 
Complete resolution by regeneration 
Repair by fibrosis and scarring 
Encapsulation by abscessation 
Persistence by granulomatous disease
31
Q

viral hepatitis

A

Adenoviruses
Herpesviruses
Coronaviruses
generally occurs in young +/or unvaccinated

32
Q

Infectious canine hepatitis

A

highly infectious disease of young dogs
long-term shedding in urine
tropism for endothelium (widespread haemorrhages, particularly on serosal surfaces) and hepatocytes
lymph nodes and tonsils enlarged and reddened, sometimes haemorrhagic
recovering animals may show an immune-mediated uveitis with corneal opacity

33
Q

Herpesviruses cause which diseases

A

Equine Viral Rhinopneumonitis
Infectious Bovine Rhinotracheitis
Feline Viral Rhinopneumonitis
Aujezsky’s disease

34
Q

herpesvirus infections

A

Liver lesions occur in aborted fetuses or neonates
pinpoint foci of necrosis with intranuclear inclusion bodies
Necrosis also occurs in lungs, kidneys, spleen and adrenal glands

35
Q

Feline infectious peritonitis

A

Enteric coronavirus mutates to cause systemic vasculitis and effusions in cats
Pyogranulomatous lesions in multiple organs including the liver
‘wet’ (effusive) or ‘dry’ (granulomatous) forms

36
Q

Bacterial hepatitis - Routes of infection - direct extension

A

from disease in adjacent tissues

37
Q

Bacterial hepatitis - Routes of infection - haematogenous

A

via the umbilical vein from infected umbilicus
via the portal vein from the alimentary tract
via the hepatic artery in bacteraemias and septicaemias

38
Q

Bacterial hepatitis - Routes of infection - hepatic abscessation

A

is particularly common in cattle
from umbilical infections - usually mixed bacteria
from rumenitis caused by overfeeding with grain

39
Q

Bacillary necrosis - caused by which bacteria

A

Fusobacterium necrophorum

40
Q

Bacillary necrosis - aetiology

A

Umbilical infection in calves

Rumenitis in adult cattle

41
Q

Bacillary necrosis - gross pathology

A

Multiple pale foci of necrosis throughout the liver

may develop into abscesses if the animal survives

42
Q

Bacillary necrosis - microscopy

A

coagulative necrosis with bacteria at periphery

43
Q

Infectious necrotic hepatitis

A
aka black disease
Sheep (rarely horses or pigs) 
Migrating immature liver flukes often precipitate disease 
Animals found dead 
Post-mortem changes occur rapidly
44
Q

Infectious necrotic hepatitis - caused by which bacteria

A

Clostridium novyi type B

45
Q

Infectious necrotic hepatitis - pathology

A

extensive subcutaneous venous congestion (‘Black disease’) and oedema
fibrinous peritoneal, thoracic + pericardial fluid
characteristic pale foci of necrosis (containing bacteria) surrounded by a rim of haemorrhage

46
Q

Bacillary haemoglobinuria - caused by which bacteria

A

Clostridium haemolyticum

47
Q

Bacillary haemoglobinuria

A

Cattle and sheep

closely related to C. novyi and the pathogenesis is similar to black disease

48
Q

Bacillary haemoglobinuria - pathology

A

Severe anaemia, jaundice, haemoglobinuria

large necrotic focus in liver + haemoglobin staining of kidneys

49
Q

tyzzers disease - caused by which bacteria

A

Clostridium piliforme

Bacillus piliformis

50
Q

tyzzers disease

A

disease of laboratory rodents
may affect foals + immunosuppressed dogs and cats
initial intestinal lesions can be hard to find at post-mortem exam
‘wheat sheaf’’ appearance of colonies when stained with a silver stain

51
Q

leptospirosis

A

zoonosis
hepatic disease in dogs
multiple serovars involved
haemolytic anaemia, widespread haemorrhages and icterus
hepatocyte dissociation (results in cholestasis) and haemosiderin accumulation (secondary to haemolysis)

52
Q

salmonellosis - clinical features

A

fever, dehydration and diarrhoea

53
Q

salmonellosis - gross pathology

A

severe, often haemorrhagic, inflammation in the ileum

pale foci of necrosis in the liver called ‘paratyphoid nodules

54
Q

salmonellosis - microscopy

A

Foci of necrosis

Mixed mononuclear inflammatory cell infiltrate

55
Q

parasites of the liver

A

usually incidental findings (excluding liver fluke)
ascaris suum migration- ‘milk spot’ liver
strongyle migration in the horse
common to find fibrous tags incidentally on the surface of the liver and adjacent diaphragm
remnants of fibrous repair following the egress of the parasites from the liver

56
Q

toxic liver disease - acute intoxication

A

causes widespread haemorrhages in the body due to excessive consumption of the clotting factors in the damaged liver coupled with failure to produce these
factors by the damaged liver
Examples are blue-green algae, iron and cresols

57
Q

toxic liver disease - chronic intoxication

A

continual ingestion of toxic compounds at low doses over a period of time
there will be evidence of regeneration and repair of the damaged tissue i.e. fibrosis and biliary hyperplasia
Examples are ragwort, aflatoxins and copper
Certain drugs are also hepatotoxic

58
Q

pathology of the gall bladder

A

Inflammation (cholecystitis) occurs in Salmonellosis and Infectious Canine Hepatitis
Hyperplasia of the mucosa is a common reaction to any irritation of this area
Gallstones (choleliths) may be found as an incidental finding

59
Q

pathology of biliary tree - obstruction

A

occurs due to parasites, sometimes gall stones (choleliths) - rare
compression of the ducts by nearby inflammatory and neoplastic processes - more common

60
Q

pathology of biliary tree - rupture of bile duct

A

serious as omentum is incapable of sealing even the smallest leaks
chronic inflammatory process; if infected widespread peritonitis

61
Q

Nodular hyperplasia - gross

A

spherical nodules in the liver

vary in colour from pale to dark or can be same colour as rest of the liver

62
Q

nodular hyperplasia - micro

A

cells are larger, may contain more glycogen
portal areas still visible within the mass
compression of adjacent normal tissue

63
Q

Neoplastic disease of the liver: primary tumours

A

Principally dogs and cats
from hepatocytes (hepatoma or hepatocellular carcinoma)
or biliary epithelium (most are cholangiocellular carcinomas)
Hepatocellular tumours may resemble normal parenchyma (with haemorrhage or necrosis in malignant tumours)
cholangiocellular carcinomas are often white, firm and umbilicate

64
Q

Neoplastic disease of the liver: metastatic tumours - Haemangiosarcoma

A

can be primary or metastatic in the liver
other predilection sites are the spleen and right auricle of the heart
prevalent in large breeds

65
Q

Neoplastic disease of the liver: metastatic tumours - secondary tumours

A

secondary metastatic involvement of the liver is very common: includes melanoma, carcinoma, sarcoma and lymphoma

66
Q

Pancreatic hypoplasia

A

developmental abnormality
German shepherd dogs and calves
occurs at about one year of age

67
Q

Pancreatic hypoplasia - clinical signs

A

steatorrhoea (fat in faeces) and diarrhoea
loss of condition despite polyphagia
pot-bellied

68
Q

Pancreatic hypoplasia - pathology

A

intestines distended by bulky fatty ingesta
lack of fat in the mesentery and abdomen
sparse pink pancreatic tissue
microscopy reveals hypoplastic acini

69
Q

Acute pancreatitis - clinical signs

A

shock and cardiovascular collapse
raised lipase and amylase levels
some cases subclinical

70
Q

Acute pancreatitis - gross

A

chalk-like areas of fat necrosis with local reddening around the pancreas
a small amount of blood-tinged fluid in the abdomen with fatty globules

71
Q

Acute pancreatitis - micro

A

haemorrhagic oedema and necrosis affecting pancreas and peripancreatic fat

72
Q

Chronic pancreatitis

A

often follows acute pancreatitis - replacement fibrosis and atrophy
leads to exocrine pancreatic insufficiency (steatorrhoea and loss of condition)
may be subclinical in cats and horses

73
Q

Pancreatic hyperplasia

A

Nodular hyperplasia is common in older dogs and (esp) cats - of no clinical significance

74
Q

Pancreatic hyperplasia - gross

A

white lobules or plaques projecting from the surface

don’t distort adjacent tissue + aren’t encapsulated

75
Q

Pancreatic hyperplasia - micro

A

similar to normal glandular tissue

76
Q

Pancreatic neoplasia

A

Adenoma - extremely rare
Carcinoma -highly invasive and infiltrative with metastases to the liver, peritoneum, abdominal lymph nodes, spleen, adrenals