Liver Pathology

Question 1

What cell type is responsible for defending the liver against bacterial and viral agents?

Answer 1

Kupffer cells

Question 2

What antibody in enterohepatic circulation is responsible for protecting against pathogens?

Answer 2

IgA

Question 3

What part of hepatocytes are responsible for defense against pathogens?

Answer 3

Phase I in the SER and phase II in the cytosol

Question 4

What change do injured hepatocytes often undergo?

Answer 4

Hydropic vacuolar change (lipidosis if mild)

Question 5

Chronic, mild injury to hepatocytes causes what change?

Answer 5

Atrophy

Question 6

What does apoptosis in the liver look like histologically?

Answer 6

Intensely eosinophilic bodies with well defined borders and a pericellular halo

Question 7

This pattern of injury consists of foci of varying sizes scattered through lobes

Answer 7

Random

Question 8

Random pattern injury is usually caused by ___

Answer 8

Infectious agents arriving via the bloodstream

Question 9

This pattern of injury is seen as all hepatocytes in defined areas of all lobules being affected to approximately the same extent

Answer 9

Zonal

Question 10

What pattern is associated with a “reticulated” liver?

Answer 10

Zonal

Question 11

With acute ___ injury, the liver overall will be swollen and friable, with rounded lobular edges

Answer 11

Zonal

Question 12

The subset of the zonal pattern of injury is the most common, with the least oxygenated hepatocytes around the central vein (zone 3) being affected

Answer 12

Centrilobular

Question 13

Hypoxia due to right sided cardiac insufficiency, anemia, or shock is a common cause of this pattern

Answer 13

Centrilobular

Question 14

Bioactivation of xenobiotics from the gut causes free radical damage in this pattern

Answer 14

Centrilobular

Question 15

This pattern (a subset of zonal) occurs when only part of zone 3 is affected; it generally precedes centrilobular pattern and has the same etiologies

Answer 15

Paracentral

Question 16

This is the rarest of the patterns (still a subset of zonal) and is most often seen in horses, pigs, and cats; it is mainly due to toxic insult (such as aflatoxin, hexachloraphene, and steroid hepatopathy)

Answer 16

Midzonal (zone 2)

Question 17

This is an uncommon pattern (subset of zonal) that reflects direct hepatocyte damage by an agent entering from the bloodstream; usually involves a “direct-acting” toxicant that does not require bioactivation

Answer 17

Periportal (zone 1)

Question 18

This subset of the zonal pattern reflects severe and extensive damage such that zones of damage begin to coalesce

Answer 18

Bridging

Question 19

This subset of the zonal pattern occurs when the entire lobule is affected; the liver acutely becomes a sac of dilated, engorged sinusoids and then the parenchyma collapses and fibrosis occurs

Answer 19

Massive

Question 20

Viruses are the least likely to induce this response and fibrosis, while bacteria and parasites are the most likely to induce this response and fibrosis

Answer 20

Inflammatory

Question 21

This condition is generally associated with an infectious agent and is random in distribution

Answer 21

Acute hepatitis

Question 22

Viral inducers of acute hepatitis cause ___ and ___ exudate

Answer 22

Necrosis

Light suppurative

Question 23

Bacterial inducers of acute hepatitis cause ___ and ___ exudate

Answer 23

Necrosis

Heavy suppurative

Question 24

Coliform bacterial inducers of acute hepatitis cause ___ or ___ exudate

Answer 24

Pyogranulomatous

Granulomatous

Question 25

Any persistent infectious agent will cause this, in which the agent is surrounded by fibrosis

Answer 25

Chronic hepatitis

Question 26

This liver condition consists of necrosis and/or apoptosis in midzonal and periportal areas; if not stopped, it can become end stage liver

Answer 26

Chronic active hepatitis

Question 27

This liver condition is often unnoticed until necropsy of an animal with a systemic infection; neutrophils and lymphocytes are sometimes seen in the portal triads as evidence the liver was dealing with an insult

Answer 27

Reactive hepatitis

Question 28

This inflammation is centered around and in cholangioles of the portal triad; N0 may be present, but it is more common for lymphocytes, macrophages, and fibrosis to be seen

Answer 28

Cholangitis

Question 29

This type of hepatitis centers around cholangioles but spreads to periportal hepatocytes; it occurs when agents such as flukes travel up the biliary tree

Answer 29

Cholaniohepatitis

Question 30

In large scale hepatocyte loss, these stem cells create replacements for the ones lost

Answer 30

Oval cells

Question 31

Regeneration without scarring occurs rapidly under what two conditions?

Answer 31

Stroma is present and severe collapse has not occured Inflammation is minimal or nonexistent (this is often the case in toxicant injury)

Question 32

Cholangioles respond to any outflow impairment via this method; it is usually associated with longstanding liver damage

Answer 32

Biliary hyperplasia

Question 33

The supporting stroma of the triads in the liver is a combination of what three types of collagen?

Answer 33

I, III, IV

Question 34

After chronic and/or repetitive injury, what cells (that normally store triglycerides) redifferentiate into myofibroblastic cells?

Answer 34

Stellate (Ito) cells

Question 35

What do redifferentiated Ito cells deposit? (2)

Answer 35

Coarse collagen I | Ground substance

Question 36

This is a diffuse process characterized by fibrosis and the conversion of the normal architecture into structurally abnormal lobules

Answer 36

End stage liver (cirrhosis)

Question 37

As part of end stage fibrosis, shunts develop between what vessels?

Answer 37

hepatic arterioles and central veins

Question 38

Regeneration of "normal" hepatocytes in end stage liver can cause what gross lesions? (2)

Answer 38

Macronodular | Micronodular

Question 39

What species are more prone to macronodular cirrhosis? (3)

Answer 39

Dogs Cats Humans

Question 40

What species are more prone to micronodular cirrhosis?

Answer 40

Horses, sheep, goats, cattle

Question 41

What type of fibrosis lends to a poor prognosis?

Answer 41

Bridging

Question 42

Approximately how much liver parenchyma needs to be lost before clinical signs manifest?

Answer 42

3/4

Question 43

Acute liver failure happens in cases of ___

Answer 43

Massive fibrosis

Question 44

Chronic liver failure happens as ___ develops

Answer 44

End stage liver

Question 45

What is the mechanism behind hepatic encephalopathy?

Answer 45

Liver failure -> loss of urea cycle -> ammonia cannot be converted to urea -> ammonia buildup in blood -> ammonia gets into PNS and CNS and damages astrocytes

Question 46

All clotting factors except ___ are synthesized in the liver; this is why bleeding often occurs in cases of liver failure

Answer 46

VIII

Question 47

Why does ascites occur with liver failure? (2)

Answer 47

Albumin not produced; cannot maintain oncotic pressure | Shunting causes hypertension, leading to leakage

Question 48

What is a cutaneous change seen in dogs and cats with liver failure?

Answer 48

Epidermal necrosis and ulceration with parakeratosis

Question 49

What is a cutaneous change seen in herbivores with liver failure?

Answer 49

Secondary photosensitization (dt buildup of phylloerythrin)

Question 50

These are normally incidental, can get quite large, reflect abnormal development of the biliary tress, and occur in dogs, cats, and pigs

Answer 50

Biliary cysts

Question 51

This mainly occurs in large animals when a ligamentous attachment causes hypoxia in an organ

Answer 51

Tension lipidosis

Question 52

This horse disease's etiology is debated (Parasites? Residual adhesions between the diaphragm and hepatic capsule? Aliens?) but the lesions associated with it are tags and plaques

Answer 52

Capsular fibrosis (fibrous tags)

Question 53

A condition of unknown etiology in which hepatocytes drop out and sinusoids dilate to fill the space, becoming irregular and blood filled; common in cattle and old cats

Answer 53

Telangiectasia

Question 54

This circulatory disorder is almost always a consequence of right sided cardiac insufficiency, with sinusoids engorging from centrilobular to entire lobule. When acute, the liver is swollen, red, spongy, and oozes blood. When chronic, the liver is large, pale, and firm.

Answer 54

Passive congestion - a disease of outflow

Question 55

This disease is often associated with plant or fungal toxicosis and is characterized by fibrosis around the centrilobular veins, leading to congestion

Answer 55

Veno-occlusive disease

Question 56

Severe acute ___ will lead to profound centrilobular hypoxia with degeneration and necrosis

Answer 56

Anemia - a disease of inflow

Question 57

Slowly developing ___ will lead to atrophy of centrilobular hepatocytes

Answer 57

Anemia

Question 58

Anemia and passive congestion both result in a ___ pattern

Answer 58

Reticular

Question 59

These may be intra or extra hepatic but usually involve one large caliber between the portal vein and vena cava; intrahepatic more common in large dogs, extrahepatic more common in small dogs

Answer 59

Congenital porto-systemic shunts

Question 60

Due to abnormal blood supply, this causes the liver to be small with poorly defined lobules, small hepatocytes, indistinct veins, and abundant arterioles

Answer 60

Congenital porto-systemic shunt

Question 61

Developing secondarily to bridging fibrosis, veno-occlusive disease, abnormally large regenerative nodules, or amyloidosis, this disease impairs flow within the portal venous system leading to pressure buildup and ascites

Answer 61

Portal hypertension

Question 62

This condition appears grossly as a large, soft, friable, pale yellow liver with a reticulated pattern and greasy texture; it can arise from metabolic disturbances as well as toxic injury

Answer 62

Lipidosis

Question 63

This condition is pathologic and occurs mainly in dogs with hyperadrenocorticism; the liver will be enlarged and slightly pale with a reticular pattern and normal texture

Answer 63

Glycogen accumulation

Question 64

Typically occurs in large animals with chronic infections and tends to be peri-sinusoidal; the liver appears smaller, pale brown, and slightly firmer than normal with a waxy texture

Answer 64

Amyloidosis

Question 65

This condition leads to acute necrosis and inflammation via free radicals, ending in end stage liver in certain sheep and dogs

Answer 65

Copper accumulation

Question 66

This accumulates in Kupffer cells due to hemoglobin breakdown and may give the liver a blackish color

Answer 66

Hemosiderin

Question 67

Wear and tear pigment

Answer 67

Lipofuscin

Question 68

Melanin in the liver of a mammal is reflective of ___

Answer 68

Congenital melanosis (pigment where it shouldn't be)

Question 69

Melanin in the liver of a bird, reptile, or amphibian is indicative of ___

Answer 69

Chronic inflammatory disease

Question 70

This virus in dogs targets hepatocytes and endothelial cells lining sinusoids and appears as an enlarged, friable liver with necrosis and a reticular pattern of small, white foci; there are blue, smudgy inclusion bodies in affected nuclei; edema of the gall bladder wall is almost diagnostic

Answer 70

Canine Adenovirus

Question 71

This virus induces random foci of necrosis and little inflammation in the liver; it is seen histologically as acidophilic intranuclear inclusion bodies

Answer 71

Herpes

Question 72

This can be either fibronous/fibrinopurulent and cover the capsular surface or granulomatous/pyogranulomatous and expand out from the triads. Meow.

Answer 72

FIP wet form and dry form

Question 73

Bacteria causing abscesses can reach the liver via these three routes

Answer 73

Portal system Umbilicus (neonates) Lung -> pulmonary veins -> L heart -> hepatic arteries

Question 74

Aerobic or facultative anaerobic bacteria tend to cause a ___ abscess while anaerobic bacteria tend to cause a ___ abscess

Answer 74

Purely suppurative | Necrotic, foul-smelling, cavitating

Question 75

Which bacteria are most responsible for abscesses in horses? (2)

Answer 75

Actinobacillus equuli | Listeria monocytogenes

Question 76

Which bacteria are most responsible for abscesses in cattle? (3)

Answer 76

Arcanobacter pyogenes Fusobacterium necrophorum Pasteurella multocida

Question 77

Which bacteria are most responsible for abscesses in sheep? (3)

Answer 77

Corynebacterium ovis Haemophilus agni Pasteurella haemolytica

Question 78

Which bacteria is most responsible for abscesses in dogs and cats?

Answer 78

Yersinia tularensis

Question 79

Which bacteria are most responsible for abscesses in rabbits? (4)

Answer 79

Pasteurella multocida Yersinia tularensis Listeria monocytogenes Streptococcus