Pathology of the liver and pacreas Flashcards Preview

Vet - notes > Pathology of the liver and pacreas > Flashcards

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

Portosystemic shunt

congenital or acquired
portal blood bypasses the liver

2

Portosystemic shunt - congenital

shunting into vena cava, azygos or renal vein
usually a single communication between the vessels

3

portosystemic shunt - acquired

shunts secondary to fibrosis in older animals
multiple thin-walled shunts

4

Congenital cysts

most are biliary
can be multiple

5

displacements

congenital or acquired

6

tension lipidosis

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

7

capsular fibrosis

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

8

telangiectasis

foci of sinusoidal dilatation
cats + cattle

9

Circulatory disorders - passive venous congestion - presentation

usually associated with right-sided heart failure acute or chronic

10

Circulatory disorders - passive venous congestion - gross pathology

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

11

Circulatory disorders - passive venous congestion - microscopy

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

12

common pigments

melanin
haemosiderin
bile
liofuscin

13

vacuolar hepatopathies

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

vacuolar hepatopathies - causes

hypoxia, mild toxic damage and metabolic stress

15

lipidosis - causes

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

Abnormal deposits and accumulations - lysosomal storage diseases

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

Abnormal deposits and accumulations - amyloidosis

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

amyloidosis - gross appearance

Liver pale, enlarged and friable – prone to rupture

19

amyloidosis - microscopic appearance

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

20

Necrosis of the liver - causes

ischaemia
toxic damage
nutritional deficiencies
microbial infection

21

necrosis - patterns

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

22

Fibrosis of the liver - Patterns of fibrosis

Periacinar fibrosis
Biliary fibrosis
Post-necrotic scarring
Cirrhosis

23

Periacinar fibrosis

fibrosis surrounds central vein
chronic passive congestion

24

Biliary fibrosis

accompanying inflammation
centred on the portal triads

25

Post-necrotic scarring

following massive necrosis

26

cirrhosis

extensive fibrotic lesions
end stage liver
may be concurrent nodular regeneration

27

hepatitis - define

Inflammation of the liver parenchyma
ften caused by infection

28

cholangitis - define

Inflammation of the bile ducts
may be immune-mediated or associated with infection (e.g. salmonellosis in calves)

29

cholangiohepatitis - define

Inflammation of parenchyma and bile ducts

30

progression of hepatitis

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

viral hepatitis

Adenoviruses
Herpesviruses
Coronaviruses
generally occurs in young +/or unvaccinated

32

Infectious canine hepatitis

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

Herpesviruses cause which diseases

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

34

herpesvirus infections

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

Feline infectious peritonitis

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

Bacterial hepatitis - Routes of infection - direct extension

from disease in adjacent tissues

37

Bacterial hepatitis - Routes of infection - haematogenous

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

38

Bacterial hepatitis - Routes of infection - hepatic abscessation

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

39

Bacillary necrosis - caused by which bacteria

Fusobacterium necrophorum

40

Bacillary necrosis - aetiology

Umbilical infection in calves
Rumenitis in adult cattle

41

Bacillary necrosis - gross pathology

Multiple pale foci of necrosis throughout the liver
may develop into abscesses if the animal survives

42

Bacillary necrosis - microscopy

coagulative necrosis with bacteria at periphery

43

Infectious necrotic hepatitis

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

44

Infectious necrotic hepatitis - caused by which bacteria

Clostridium novyi type B

45

Infectious necrotic hepatitis - pathology

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

Bacillary haemoglobinuria - caused by which bacteria

Clostridium haemolyticum

47

Bacillary haemoglobinuria

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

48

Bacillary haemoglobinuria - pathology

Severe anaemia, jaundice, haemoglobinuria
large necrotic focus in liver + haemoglobin staining of kidneys

49

tyzzers disease - caused by which bacteria

Clostridium piliforme
(Bacillus piliformis)

50

tyzzers disease

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

leptospirosis

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

salmonellosis - clinical features

fever, dehydration and diarrhoea

53

salmonellosis - gross pathology

severe, often haemorrhagic, inflammation in the ileum
pale foci of necrosis in the liver called ‘paratyphoid nodules

54

salmonellosis - microscopy

Foci of necrosis
Mixed mononuclear inflammatory cell infiltrate

55

parasites of the liver

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

toxic liver disease - acute intoxication

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

toxic liver disease - chronic intoxication

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

pathology of the gall bladder

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

pathology of biliary tree - obstruction

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

60

pathology of biliary tree - rupture of bile duct

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

61

Nodular hyperplasia - gross

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

62

nodular hyperplasia - micro

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

63

Neoplastic disease of the liver: primary tumours

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

Neoplastic disease of the liver: metastatic tumours - Haemangiosarcoma

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

Neoplastic disease of the liver: metastatic tumours - secondary tumours

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

66

Pancreatic hypoplasia

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

67

Pancreatic hypoplasia - clinical signs

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

68

Pancreatic hypoplasia - pathology

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

69

Acute pancreatitis - clinical signs

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

70

Acute pancreatitis - gross

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

Acute pancreatitis - micro

haemorrhagic oedema and necrosis affecting pancreas and peripancreatic fat

72

Chronic pancreatitis

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

Pancreatic hyperplasia

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

74

Pancreatic hyperplasia - gross

white lobules or plaques projecting from the surface
don't distort adjacent tissue + aren't encapsulated

75

Pancreatic hyperplasia - micro

similar to normal glandular tissue

76

Pancreatic neoplasia

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