Pathology Of The Liver And Pancreas Flashcards
1
Q
List the key functions of the liver
A
Protein synthesis - clotting factors and albumin
Metabolism - detoxification (e.g. ammonia)
Excretion and digestion - bilirubin and bile
Nutrition - regulation of fat and carbs
2
Q
Describe the normal level of oxygen of the liver.
A
Poorly oxygenated
3
Q
Describe the blood supply to the liver
A
75% from Portal vein (w/ nutrients)
25% from Hepatic artery (w/ oxygen)
4
Q
Describe a liver lobule
A
2mm diameter
Hexagonal
Bounded by several portal tracts - portal vein, hepatic artery, bile duct
5
Q
Describe the flow of blood in the liver
A
From branch of portal vein and branch of hepatic artery on periphery of lobule
Mix on way to central vein
Blood moves from outside of lobules into the centre
6
Q
Describe the flow of bile in the liver lobule
A
Bile is produced in canaliculi
Flows in the opposite direction to blood in the bile ducts
7
Q
What are the three hepatic zones?
A
- Periportal (centroacinar)
- AROUND THE OUTSIDE - Midzonal
- middle - Centrilobular (periacinar)
- IN THE MIDDLE
8
Q
What hepatic zone is where most injuries occur?
A
Centrilobular (periacinar)
9
Q
Which zone is most poorly oxygenated and is most affected by ischaemia?
A
Centrilobular
10
Q
Which zone has the highest P450 cytochromes?
A
Centrilobular
11
Q
Describe the histology of the portal vein.
A
Big, thin walled
12
Q
Describe the histology of the hepatic artery
A
Smaller, thicker wall
13
Q
Describe the epithelial lining of the bile duct
A
Tall, cuboidal columnar epithelium
14
Q
Describe the shunt observed in a congenital PSS.
A
Usually single
To vena cava, azygous vein, renal vein
15
Q
Describe the shunt observed in an acquired PSS.
A
multiple thin-walled shunts
16
Q
How can an acquired shunt occur?
A
Secondary to fibrosis in older animals
17
Q
How can a PSS affect the liver?
A
Causes atrophy
18
Q
What other effect can a PSS have?
A
HE
Ammonia - neurotoxic
19
Q
What congenital/developmental disorders can affect the liver?
A
Congenital cysts Displacements Tension lipidosis Capsular fibrosis - fibrous tags (e.g. equine liver capsule) Telangiectasis - focal sinusoidal Melanosis
INCIDENTAL LESIONS
20
Q
Define telangiectasis
A
Dilation of the capillaries causing them to appear as small red or purple clusters, often spidery in appearance
Seen on the skin or the surface of an organ
21
Q
How can you tell if a liver is enlarged?
A
Rounded edges
Cutting through might tell you why e.g. if congested
22
Q
What can cause a vacuolar hepatopathy?
A
Anything with swelling and vacuolation of the hepatocytes.
Water- hydropic, Fat - lipidosis, glycogen - glycogenosis
23
Q
Describe the typical distribution seen with a vacuolar hepatopathy
A
Usually zonal or diffuse
24
Q
Describe the features of hydropic change.
A
Common
Non specific
Reversible
25
What can cause vacuolar hepatopathy?
Hypoxia
mild toxic damage
Metabolic stress
26
What can cause glycogenosis?
Hyperadrenocorticism
| Steroids
27
What dietary factors can result in lipidosis?
Obesity
| Starvation
28
What physiological factors can cause lipidosis?
Increased energy demand e.g. lactation and pregnancy
29
What diseases can cause hepatic lipidosis?
Diabetes mellitus
Ketosis
Pregnancy toxaemia
30
How can abnormal hepatocyte function result in lipidosis?
Decreased FA complexing
| Decreases LDLs
31
Describe the appearance of a liver with amyloidosis
Pale orange
| Friable
32
Describe the histology of a liver with amyloidosis
Homogenous acidophilus material
Special stain - Congo red - fluorescence (green birefringence)
33
What animals are predisposed to hepatic amyloidosis?
Abyssinian/ oriental cats
34
What can cause amyloidosis?
Primary or secondary liver disease
Endocrinopathy
35
What can cause centrilobular necrosis?
Ischaemia/anaemia
| Metabolic/toxic damage
36
What would a zonal necrosis pattern suggest?
Ischaemia,
Toxic damage
37
What would a random pattern of necrosis suggest?
Viral/ bacterial
38
What does a focally extensive pattern of necrosis indicate?
Bacterial cause
39
What does massive necrosis indicate?
Severe injury/ toxicity
E.g. hepatosis dietetics
40
What is hepatosis dietetica?
What species does it typically affect?
Selenium/vitamin E deficiency
Presentation: sudden death
PM - large areas of hepatic necrosis and haemorrhage
- gall bladder oedematous
PIGS - young - 3/4 months
41
What does ascites indicate about oncotic pressure?
REDUCED
42
When is cirrhosis seen?
End stage liver disease
43
How can RCHF affect the liver?
Passive venous congestion
44
Describe the gross pathology associated with passive venous congestion.
Enlarged,
Rounded edges,
Blood from cut surface
NUTMEG LIVER - enhanced lobular pattern
45
Describe the histology associated with passive venous congestion.
Hepatic venules and sinusoids congested
Centrilobular atrophic hepatocytes (DARK RED)
Periportal lipidosis (pale red)
46
What is cholangitis?
Inflammation of the bile ducts
Can be immune mediated or associated with infection
47
What species is associated with immune mediated cholangitis ?
Cats
48
What affect on the liver can salmonellosis in calves have?
Cholangitis
49
What broadly occurs in acute hepatitis?
Necrosis followed by inflammation
50
If the animal survives, what progression follows from acute hepatitis?
- Complete resolution by regeneration
- Repair by fibrosis and scarring
- Encapsulation by abscessation
- Persistence by granulomatous disease
51
What can cause viral hepatitis?
What animals are these seen in?
Adenoviruses
Herpesviruses
FIP
Young, unvaccinated animals
52
What does adenovirus cause in dogs?
Canine infectious hepatitis
53
What herpesvirus is associated with abortions in horses?
EHV-1
54
What (herpes)viral conditions are associated with abortions in cows, cats and pigs?
Infectious bovine rhinotracheitis
Feline viral rhinotracheitis
Aujeszky’s disease
55
What liver lesions would you expect to see in an aborted foetus from a herpes virus infection?
Pinpoint foci of necrosis
Intranuclear inclusions
Necrosis also seen in lungs, kidneys, spleen, adrenals
56
What are the routes of infection with bacterial hepatitis?
Direct extension from adjacent tissues
Haematogenous spread
Abscessation
57
What are the sources of haematogenous bacteria?
Portal vein from alimentary tract
Hepatic artery - if a bacteraemia
Umbillicus/umbilical vein
58
What animals tend to get liver abscesses?
Cows
59
What is the source of most liver abscesses in cows?
Umbilical infections (usually mixed bacteria)
From grain overfeeding - rumenitis
60
What can cause a bacterial hepatitis?
```
Fusobacterium necrophorum
Clostridium novyi B
Clostridium haemolyticum
Clostridium piliformis
Leptospirosis
Salmonellosis
Listeria
```
61
What causes Tyzzer’s disease?
What animals are particularly susceptible?
Clostridium pilformis
Mice (+rats, gerbils)(rodents)
Foals - 1-4 weeks old
Immunosuppressed dogs and cats
62
What causes bacilliary haemoglobinuria?
Clostridiumhaemolyticum
63
What causes bacillary necrosis?
Fusobacterium necrophorum
64
What causes Black disease (Infectious, necrotic hepatitis)?
Clostridium novyi type B
65
What is the source of fusobacterium necrophorum in bacillary necrosis:
- in neonates?
- in adults?
Neonates - UMBILICAL
Adults - RUMENITIS
66
Describe the gross pathology associated with fusobacterium necrophorum.
Multiple pale foci of necrosis throughout the liver
| May develop into abscesses if the animal survives
67
What is seen on microscopy with bacillary necrosis?
Coagulation necrosis with bacteria at periphery
68
What animals tend to get black disease?
Sheep
| Rarely horses and pigs
69
What precipitates Clostridium novyi B?
LIVER FLUKES
70
What clinical presentation is associated with clostridium novyi B infection ?
SUDDEN DEATH
71
What pathology is associated with black disease?
Extensive subcutaneous venous congestion and oedema
Fibrinous peritoneal, thoracic and pericardial fluid
Pale foci of liver necrosis (containing bacteria) surrounded by a rim of haemorrhage
72
What species get bacillary haemaglobinuria?
Cattle and sheep
73
What clinical sign is associated with bacillary haemaglobinuria?
Haemaglobin in urine - ‘red water’
Severe anaemia
Jaundice
74
What can be seen on PM with bacillary haemaglobinuria?
Focally extensive hepatic necrosis
Haemaglobin staining of kidneys
75
Describe the lesions seen in tyzzer’s disease
Liver filled with nodules of necrosis
76
Describe the histology of tyzzer’s
Wheat sheaf appearance of colonies with special stain
77
What infections tend to cause focally extensive/ abscessating lesions?
Bacteria
78
What clinical signs are associated with salmonellosis in calves?
Fever, dehydration, diarrhoea
Haemorrhagic ileitis
Pale pinpoint foci of necrosis in liver
Necrosis and mixed mononuclear cells
79
How can the nodules in the liver of a calf with salmonellosis be described?
Paratyphoid nodules
80
Which parasites of the liver are NOT incidental?
FLUKE
81
What causes ‘milk spot liver’ ?
Ascaris Suum
82
What causes fibrous tags on horse liver?
Strongyle migration
tags seen on liver surface and diaphragm
83
How does acute liver intoxication occur?
HAEMORRHAGE occurs ->
Increased consumption and decreased synthesis of clotting factors by damaged liver - Jaundice
E.g. blue-green algae, iron and cresols
84
How does chronic liver intoxication occur?
Continual low dose toxic compounds
Regeneration and repair - fibrosis and biliary hyperplasia
E.g. ragwort, aflatoxins (produced by moulds), copper
Drugs: primidone, sulphonamides, paracetamol (CATS)
85
What drugs can cause chronic liver intoxication?
Primidone - phenobarb analogue (anticonvulsant)
Paracetamol (CATS)
Sulphonamides
86
What infectious conditions cause cholecystitis (Gall bladder + extrahepatic bile duct)?
SALMONELLA
INFECTIOUS CANINE HEPATITIS
87
What can occur if the gall bladder /extrahepatic duct ruptures ?
BILE PERITONITIS
88
What would make you suspect that a liver nodule is an incidental finding?
If they look the same as the rest of the liver
89
In what animals is nodular hyperplasia common?
Older dogs
90
How do the cells appear in nodular hyperplasia?
Cells are larger. Contain more glycogen
91
Which animals tend to get liver neoplasms?
Dogs and cats
92
What primary tumours of hepatocytes can occur?
Hepatoma / hepatocellular carcinoma
93
What is the most common neoplasm of the biliary epithelium?
Cholangiocellular carcinoma
94
Describe the typical appearance of a cholangiocellular carcinoma.
White, firm and umbilicate (depression in the middle)
95
What hepatic neoplasm can be primary or metastatic?
Haemangiosarcoma
96
Where are primary haemangiosarcoma usually found?
Spleen
| Right auricle
97
What tumours tend to metastasise to the liver?
Melanoma
Carcinoma
Sarcoma
Lymphoma
98
What breeds are predisposed to haemangiosarcoma?
Large dogs
99
What animals tend to get pancreatic hypoplasia?
GSDs
| Calves
100
When do clinical signs of pancreatic hypoplasia tend to be seen?
Around a year old
101
What clinical signs are associated with pancreatic hypoplasia?
Diarrhoea + steatorrhaea
Loss of condition despite polyphagia
Pot bellied
Lack of abdominal fat
102
Define the term : steatorrhoea
Abnormally high levels of fat in faeces
103
What type of pancreatic neoplasia is most common?
Carcinoma
104
Describe a pancreatic carcinoma
```
Highly invasive
Infiltrative with mets to:
-liver
-abdominal LNs
- spleen
- adrenals
```
105
How does chronic pancreatitis occur in dogs?
Acute pancreatitis
Replacement fibrosis and atrophy
EPI - steatorrhoea and loss of condition
106
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