Pathology: Hepatobiliary

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Questions and Answers

What percentage of the liver is typically non-functional in cases of liver failure?

70-80% (correct)

50-60%

60-70%

80-90%

What is the primary characteristic of chronic liver failure?

Progression over months or years (correct)

Rapid onset of symptoms

Reversible hepatic dysfunction

Acute liver injury

Which condition describes the inflammation of the liver parenchyma?

Cirrhosis

Hepatitis (correct)

Cholecystitis

Cholangitis

Which of the following conditions can lead to cholestasis?

Biliary obstruction Signup and view all the answers

What is the end-stage result of chronic liver disease known as?

Cirrhosis Signup and view all the answers

Which term describes inflammation that affects both the bile ducts and adjacent hepatic parenchyma?

Cholangiohepatitis Signup and view all the answers

What typically happens to the liver in end-stage liver failure?

It becomes smaller, paler, and firmer Signup and view all the answers

Which of the following can cause acute liver failure?

Acute toxicity Signup and view all the answers

What is the primary component that bile consists of?

Water, cholesterol, bile acids, and waste products Signup and view all the answers

Which of the following substances is detoxified by the liver?

Drugs and toxins Signup and view all the answers

What is the role of Kupffer cells in the liver?

Phagocytosis of aged erythrocytes and pathogens Signup and view all the answers

In cases of liver disease, which process might typically lead to the formation of new liver tissue?

Regeneration Signup and view all the answers

What characteristic is associated with fibrosis in the liver?

Paler and smaller affected areas Signup and view all the answers

What occurs in the liver after the surgical removal of up to 70% of its mass?

The liver can return to normal size and function quickly Signup and view all the answers

Biliary hyperplasia is typically caused by which of the following?

Obstruction of bile ducts or severe hepatocyte injury Signup and view all the answers

What primarily happens to the liver as a response to chronic or severe injury?

Development of fibrosis Signup and view all the answers

Which of the following is a crucial function of bile acids in the digestive process?

Lipid digestion Signup and view all the answers

What happens histologically during necrosis of liver cells?

Cell death takes place Signup and view all the answers

What is the importance of the sinusoids in the liver's structure?

To allow blood flow through with Kupffer cells present Signup and view all the answers

Which of the following does NOT form a component of bile?

Hemoglobin Signup and view all the answers

What is a characteristic of the liver's regenerative capacity?

It can handle significant damage without consequences Signup and view all the answers

What is a major role of the liver related to vitamin metabolism?

Synthesis of proteins like albumin Signup and view all the answers

What does an increase in ALT primarily indicate?

Acute hepatocellular injury Signup and view all the answers

Which of the following enzymes is considered a leakage enzyme?

AST Signup and view all the answers

Which condition is most likely indicated by increased levels of ALP and GGT?

Cholestasis Signup and view all the answers

Which of the following best describes the timing of ALT elevation following liver injury?

Increases within 12 hours, peaks at 48 hours. Signup and view all the answers

What can the presence of azotaemia indicate?

Possible pre-renal, renal, or post-renal issues Signup and view all the answers

In dogs and cats, which enzyme reflects both hepatocellular injury and muscle injury?

AST Signup and view all the answers

Which condition can result in a mild increase in ALT in older animals?

Incidental aging changes Signup and view all the answers

What differentiates induction enzymes from leakage enzymes in terms of how they increase?

Induction requires time to increase; leakage occurs rapidly after damage. Signup and view all the answers

Which of the following is NOT a likely cause for increased activity of liver enzymes?

Normal liver function Signup and view all the answers

Which factor significantly complicates the interpretation of increased ALT levels?

Variety of possible underlying diseases Signup and view all the answers

What should further diagnostics include after detecting an increased ALT?

Comprehensive CBC and urinalysis Signup and view all the answers

What is a common cause of hyperproteinaemia to be aware of?

Dehydration Signup and view all the answers

What enzyme increase is often a sign of stress rather than inflammation?

WBC parameters Signup and view all the answers

What should be monitored to assess the reversibility of liver injury?

Serum bile acids Signup and view all the answers

What is a likely indicator of adequate colostrum absorption in neonates?

Increased levels of GGT Signup and view all the answers

What parameter would indicate a marked increase in liver enzyme activity?

A value of 15 mmol/L when the reference range is 5-10 mmol/L Signup and view all the answers

Which of the following statements is true about liver function tests compared to enzyme tests?

Liver function tests assess liver's unique functional capacity. Signup and view all the answers

What substance's increase in the serum is generally associated with liver dysfunction?

Bilirubin Signup and view all the answers

Which type of hyperbilirubinaemia is indicated by acute haemolytic diseases?

Pre-hepatic hyperbilirubinaemia Signup and view all the answers

What is a typical result of fasting hyperbilirubinaemia in horses?

Mild increase in unconjugated bilirubin Signup and view all the answers

What condition might lead to post-hepatic hyperbilirubinaemia?

Bile duct obstruction Signup and view all the answers

What can increase the levels of corticosteroids in a neonatal animal's serum GGT?

Stressful environmental conditions Signup and view all the answers

Which form of bilirubin is water soluble and excreted in bile?

Conjugated bilirubin Signup and view all the answers

What does a significant elevation of GGT in a neonatal animal often indicate?

Colostrum intake Signup and view all the answers

What results from cholestasis in the liver?

Obstruction of bile flow Signup and view all the answers

In adults, which of the following can lead to mild hyperbilirubinaemia?

Fat mobilization during fasting Signup and view all the answers

Which parameter is generally lower in cases of liver dysfunction?

Albumin Signup and view all the answers

What is a potential outcome of liver injury that indicates irreversible damage?

End-stage liver or cirrhosis Signup and view all the answers

Which clinical sign is commonly associated with advanced liver disease?

Severe lethargy Signup and view all the answers

What is jaundice primarily indicative of in liver disease?

Impaired bilirubin processing Signup and view all the answers

What does hyperbilirubinaemia indicate when bilirubin levels are above 45-50μmol/L?

Potential liver dysfunction Signup and view all the answers

What could cause platelet dysfunction in an animal with advanced liver disease?

Reduced production of coagulation factors Signup and view all the answers

Which of the following is a nonspecific sign of liver disease?

Vomiting Signup and view all the answers

What finding in blood work may indicate liver dysfunction in animals?

Increased bile acids Signup and view all the answers

What is a common effect of liver failure related to plasma proteins?

Decreased production of global proteins Signup and view all the answers

What is the primary factor for photosensitisation in herbivores with liver disease?

Accumulation of phytoporphyrins Signup and view all the answers

What type of fluid is typically seen in patients with ascites due to liver disease?

Transudate Signup and view all the answers

What diagnostic method may help determine the disease process in the liver?

Fine needle aspirate Signup and view all the answers

When might an exploratory laparotomy be indicated in liver diagnostics?

When non-invasive tests are inconclusive Signup and view all the answers

What is the consequence of the liver's inability to convert ammonia in advanced liver disease?

Hepatic encephalopathy Signup and view all the answers

How can liver disease affect the body’s immune response?

By reducing the effectiveness of immune factors Signup and view all the answers

What does an increase in both AST and CK indicate?

Muscle damage Signup and view all the answers

What is the primary function of GLDH as a diagnostic enzyme in large animals?

Identify acute hepatocellular injury Signup and view all the answers

Which enzyme is a sensitive but non-specific indicator of cholestasis in dogs and cats?

ALP Signup and view all the answers

In cats, what typically happens to ALP levels in comparison to bilirubin levels during cholestasis?

Bilirubin increases before ALP Signup and view all the answers

What conditions can contribute to increased ALP due to the bone isoform?

Bone growth in young animals Signup and view all the answers

How is increased GGT typically interpreted in the context of liver health?

It serves as a major indicator of cholestasis Signup and view all the answers

What must be considered when interpreting increased ALP levels?

Other clinical signs and history Signup and view all the answers

Which condition is least likely to cause an increase in ALP levels?

Myocardial infarction Signup and view all the answers

What is the role of CK in the context of AST increases?

Helps exclude muscle damage Signup and view all the answers

What must be true for increased AST to more likely indicate liver damage?

No evidence of hemolysis must be present Signup and view all the answers

Which factor is primarily responsible for significant ALP increases due to drug administration in dogs?

Corticosteroids Signup and view all the answers

Which of the following is a possible cause of increased GGT levels aside from cholestasis?

Ingestion of colostrum in neonates Signup and view all the answers

What is the primary use of the enzyme ALP in dogs and cats?

Indicate liver function Signup and view all the answers

What happens to gold while there is significant impairment of hepatic function?

Blood ammonia levels increase. Signup and view all the answers

Which crystals may be found in the urine of animals with decreased liver function?

Ammonium biurate crystals. Signup and view all the answers

What is the primary contributor to sepsis-associated hyperbilirubinaemia?

Reduced transport proteins for bilirubin Signup and view all the answers

How does significant impairment of hepatic function affect coagulation factors?

Decreased production, leading to longer clotting times. Signup and view all the answers

What does the presence of jaundice indicate in an animal?

Hyperbilirubinaemia with visible yellow discolouration Signup and view all the answers

When does bilirubinuria generally suggest significant clinical disease in felines?

When urine is dilute Signup and view all the answers

Which of the following can result from hepatic dysfunction in terms of cholesterol metabolism?

Variable cholesterol levels with possible hypocholesterolaemia. Signup and view all the answers

What could cause an increase in serum bile acids?

Decreased functional liver mass Signup and view all the answers

Which method tends to provide more diagnostic information about liver pathology?

Liver biopsy for histology. Signup and view all the answers

Why is it necessary to collect two serum bile acid samples in dogs and cats?

To improve test sensitivity and specificity Signup and view all the answers

In the context of glucose metabolism, significant hepatic impairment can lead to which of the following situations?

Possible fluctuation between hypoglycaemia and hyperglycaemia. Signup and view all the answers

What is a likely effect of significant hepatic dysfunction on serum albumin levels?

Decreased serum albumin levels. Signup and view all the answers

What is the usual significance of hypoalbuminaemia in cases of chronic liver failure?

It is not typically evident in chronic liver failure Signup and view all the answers

What is a key point regarding bile acids as a diagnostic tool?

They indicate further diagnostic testing is needed Signup and view all the answers

Which factor is most likely to be accurate when evaluating liver function through blood tests?

Variable glucose levels. Signup and view all the answers

What is a risk associated with performing cytology through fine needle aspirates (FNAs) in cases of suspected liver disease?

Potential for liver hemorrhage. Signup and view all the answers

What effect does cholestasis have on serum bile acids?

Increased levels due to regurgitation into blood Signup and view all the answers

What factor does not typically contribute to the determination of hyperbilirubinaemia causes?

Animal's color pattern Signup and view all the answers

Which factor can lead to negligible changes in serum chemistry for cholesterol in cases of liver disease?

Mild liver damage. Signup and view all the answers

Which methodology requires a greater degree of organization and planning when diagnosing liver pathology?

Histology and biopsy. Signup and view all the answers

Which liver function test is specifically mentioned as not routinely requested?

Bile acids Signup and view all the answers

Which of the following statements about liver sampling is true?

Histology provides insights into tissue architecture. Signup and view all the answers

In what condition is bilirubinuria most clinically significant in dogs?

1+ bilirubin in dilute urine Signup and view all the answers

What is the relationship between hypoalbuminaemia and blood calcium levels?

Hypoalbuminaemia can lead to low blood calcium Signup and view all the answers

In cases of liver dysfunction, what can impact glucose metabolism unpredictably?

Effect of hepatic gluconeogenesis. Signup and view all the answers

What is a potential consequence when hepatobiliary disease affects bile excretion?

Decreased biliary excretion of cholesterol. Signup and view all the answers

What must be established before considering bile acids testing in a jaundiced animal?

Presence of hemolytic and sepsis-associated conditions Signup and view all the answers

What is the most common metastatic neoplasm found in the liver across various species?

Lymphoma Signup and view all the answers

Which characteristic is most likely to be observed in a liver affected by lymphoma?

Multiple soft cream nodules Signup and view all the answers

What distinguishes haemangiosarcoma in the liver from telangiectasis?

Haemangiosarcoma typically appears as larger, more nodular masses. Signup and view all the answers

Which statement is accurate regarding the appearance of benign liver masses?

Benign masses are usually associated with hepatocellular adenoma. Signup and view all the answers

What clinical sign might a dog with ruptured haemangiosarcoma exhibit?

Abdominal distension with fluid wave Signup and view all the answers

Which type of mass presentation in the liver indicates a higher likelihood of malignancy?

Multiple large or necrotic masses Signup and view all the answers

What is a common site for the primary tumor when there is secondary hepatic neoplasia?

Lymph nodes Signup and view all the answers

Which type of liver mass is most associated with concurrent splenic involvement?

Lymphoma Signup and view all the answers

Study Notes

Overview of Liver Disease

Liver disease encompasses various conditions like hepatitis, neoplasia, and abscessation affecting hepatic function.
Not all liver diseases exhibit clinical signs or blood changes; the liver often maintains functionality during early stages.

Liver Failure

Liver failure occurs when 70-80% of liver function is compromised, presenting significant clinical signs and blood changes.
Can be classified as acute (rapid onset without prior disease) or chronic (gradual dysfunction over months or years).
Acute liver failure may resolve with treatment, while chronic liver failure progresses to end-stage liver failure.

Cirrhosis

Cirrhosis represents the irreversible end stage of chronic liver disease, characterized by diffuse hepatic fibrosis and smaller, firmer liver appearance.
Cirrhosis leads to chronic liver failure, with severe functional impairment.

Common Liver Conditions

Cholestasis: Reduced bile secretion leading to bilirubin and bile acid accumulation, potentially caused by biliary obstruction.
Hepatitis: Inflammation of the liver, with varied causes (infectious, toxic, immune-mediated).
Cholangitis: Inflammation of the biliary tract; Cholangiohepatitis involves both bile ducts and liver.
Cholecystitis: Inflammation of the gallbladder.

Hepatic Structure and Function

The liver is the largest internal organ, comprising 1-3% of body weight in adults and up to 6-7% in neonates.
Structure consists of a smooth capsule and dark red parenchyma, with lobes varying by species.
Hepatocytes function in bile production; bile aids in fat digestion and waste excretion.

Key Metabolic Functions

Bile and bilirubin metabolism, including lipid digestion, waste elimination, and recycling of bile acids.
Carbohydrate, lipid, and vitamin metabolism, including synthesis of glucose and essential vitamins.
Protein synthesis for plasma proteins and coagulation factors.
Detoxification and storage of waste products and metals; liver modifies substances from the gastrointestinal tract before systemic circulation.
Immunity through the production of acute phase proteins and residence of immune cells.

Liver Response to Injury

Short-term responses include degeneration (reversible) or necrosis (irreversible).
Histological examination can identify specific patterns indicating disease.
Long-term responses may involve regeneration (up to 70% removal tolerance), fibrosis (chronic damage), and biliary hyperplasia (bile duct response).

Clinical Signs of Hepatobiliary Dysfunction

Significant clinical signs indicate severe liver damage or biliary obstruction.
Initial symptoms may be mild or non-specific, like anorexia, weight loss, and vomiting.
Advanced signs may include jaundice, edema, neurological symptoms, and increased bleeding risk.
Jaundice occurs due to the liver's inability to process bilirubin, evident when serum levels exceed 45-50 μmol/L.

Laboratory Evaluation

Laboratory tests are essential for diagnosing hepatobiliary disease, as clinical signs can be non-specific.
Serum liver markers include leakage enzymes (ALT, AST) indicating hepatocellular damage, and induction enzymes (ALP, GGT) indicating cholestasis.
ALT is liver-specific and indicates recent hepatocyte injury; increases in ALT can signal various underlying conditions.
AST is less specific and can indicate liver or muscle injury.

Clinical Pathology in Liver Disease

Evaluation of red blood cell parameters helps differentiate regenerative from non-regenerative anemia.
Leukogram analysis assesses inflammation versus stress responses.
Urinalysis and serum tests (urea and creatinine levels) can determine azotaemia type.
Serum glucose, protein levels, and enzyme activities provide insights into hepatobiliary function.

Key Points to Remember

Liver disease presents with a spectrum of symptoms; diagnosis often requires combining clinical findings with laboratory tests.
The liver's high regenerative capacity allows recovery from mild injury, while severe damage may lead to irreversible conditions like cirrhosis.
Diagnostic interpretation of liver enzymes is crucial, understanding they reflect hepatocyte function but do not indicate liver function or prognosis on their own.### AST and Liver Function
Increased AST may indicate damage to liver, cardiac, or skeletal muscle, alongside hemolysis.
Concurrent measurement of creatine kinase (CK) and packed cell volume (PCV) is essential to differentiate non-hepatic causes of elevated AST.
AST levels return to normal faster than ALT and GLDH due to having a shorter half-life.
Elevated AST with high CK suggests muscle damage; elevated AST with normal CK and no hemolysis indicates likely liver damage.

GLDH and ALP

GLDH is a liver-specific enzyme, indicating hepatocellular injury, primarily used in large animals.
ALP is a non-specific induction enzyme in dogs and cats; not as useful in large animals.
Increased ALP can arise from various sources, making interpretation complex—differentiation of isoforms is critical.

Hepatic ALP Isoform

Hepatic ALP is a nonspecific cholestasis indicator in dogs and cats; its elevation often precedes bilirubin increases in dogs.
Cats typically show increased bilirubin before ALP elevation due to the shorter half-life of hepatic ALP.

Bone ALP Isoform

Increases are seen in growing animals and diseases that affect bone activity, such as osteosarcoma or healing fractures.

Corticosteroid-Induced ALP Isoform

Glucocorticoids induce significant ALP increases, particularly relevant in dogs with conditions like Cushing's disease.

GGT Overview

GGT is a mainly liver-specific induction enzyme, increasingly used in both large and small animals.
Commonly indicates cholestasis, with different underlying causes in large animals and pets.
GGT levels can reflect colostrum intake in neonates, often indicative of good health.

Magnitude of Changes

Qualifying the degree of parameter changes (e.g., ALT) is essential: mild, moderate, marked.
Magnitude may provide insight into the cause and relevance of the observed change.

Liver Function Tests

Distinct from enzyme tests, liver function tests assess the liver's ability to perform essential functions.
Key substances evaluated include bilirubin, bile acids, albumin, urea, cholesterol, glucose, and coagulation factors.

Bilirubin Dynamics

Bilirubin is produced from hemoglobin breakdown; its forms (unconjugated and conjugated) play a key role in liver function.

Causes of Hyperbilirubinaemia

Fasting animals may show increased unconjugated bilirubin, particularly in horses.
Pre-hepatic (hemolytic) causes are common with diseases leading to increased bilirubin formation.
Hepatic hyperbilirubinaemia occurs in liver dysfunction, while post-hepatic (cholestatic) can occur due to bile flow obstruction.

Bile Acids

Elevated serum bile acids indicate liver disease and dysfunction, requiring further diagnostic testing.
Two samples (pre- and post-prandial) are preferred in dogs and cats for enhanced diagnostic reliability.

Albumin and Plasma Proteins

Albumin synthesis depends on liver function; hypoalbuminaemia indicates chronic liver impairment.
A:G ratio decrease often accompanies hypoalbuminaemia in liver disease.

Urea and Ammonia Considerations

Normal breakdown of protein produces ammonia, converted to urea by the liver; impairment results in elevated ammonia and low urea.

Cholesterol and Glucose in Liver Function

Cholesterol metabolism may be impacted by liver failure, potentially leading to hypocholesterolaemia.
Glucose levels can be variable in liver dysfunction, reflecting unreliable hepatic function.

Coagulation Factors

Liver impairment often results in decreased production of coagulation factors, evidenced by prolonged PT and APTT.### Liver Function and Assessment
Impaired liver function affects the synthesis of crucial compounds, leading to decreased levels of albumin, urea, and coagulation factors.
Glucose and cholesterol levels may fluctuate, with significant decrease manifesting only after 70-80% loss of liver function.
Milder liver damage usually does not show alterations in serum biochemistry.

Diagnostic Methods

Blood tests primarily assess liver damage but do not specify the cause.
In cases with liver disease but unresponsive to treatment, advanced imaging or surgery may necessitate direct liver sampling.

Sampling Techniques

Cytology (Fine Needle Aspiration - FNA)
- Involves inserting a needle to extract cells from the liver using a trans-abdominal or trans-thoracic approach.
- Effective for diffuse liver conditions; critical area sampling is less important if liver is diffusely affected.
- Ultrasound guidance is recommended, especially for focal lesions, to prevent sampling normal tissue.
- Fast, inexpensive, and typically performed without sedation; rare complications like hemorrhage can occur.
- Limited diagnostic capability compared to histology, lacking information on tissue architecture and potentially missing target areas.
Histology (Biopsy)
- Involves excising a small section of liver tissue for examination under a microscope after being preserved in formalin.
- Provides a more detailed analysis of liver tissue architecture and cellular characteristics, aiding in specific diagnosis.

Secondary Hepatic Neoplasia

Secondary hepatic neoplasia results from malignant tumors originating in other body parts that metastasize to the liver.
Particularly common in dogs and cats, reflecting a high prevalence among multiple species.

Lymphoma

Lymphoma is the most prevalent metastatic neoplasm in the liver across all species.
Characterized by a diffusely enlarged and pale liver or multiple soft cream nodules within the hepatic parenchyma.
Primary tumor sites can include lymph nodes and the gastrointestinal tract (GIT), often with concurrent splenic involvement.

Haemangiosarcoma

Commonly metastasizes to the liver in dogs, less frequently observed in cats.
Liver haemangiosarcomas resemble splenic and right atrial haemangiosarcomas, forming large, dark red nodules filled with blood when cut.
Can lead to rupture in situ, causing haemoabdomen, indicated by abdominal distension and presence of blood during abdominocentesis.

Clinical Presentation

Dogs affected by haemangiosarcoma may show signs of collapse and hemorrhagic anemia, or may die suddenly due to significant acute blood loss.
Distinguish between haemangiosarcoma and telangiectasis, which also presents as dark red and blood-filled but is usually smaller and nodular and considered benign.

Gross Appearance Interpretations

Small, single masses are typically BENIGN, such as hepatocellular adenoma or nodular hyperplasia.
Malignant conditions are often indicated by multiple masses, involvement in various locations, large size, or necrosis; examples include hepatocellular adenocarcinoma and metastases.
Lymphoma consistently appears as pale or cream-colored masses or diffuse pale enlargement in affected organs, including the liver.
Haemangiosarcoma often manifests as multiple dark red and bloody masses in different organs, including the liver; however, telangiectasis may occasionally mimic this appearance.

Diagnostic Considerations

Accurate identification of specific tumor types usually requires histological examination or cytology.

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Test your knowledge on liver failure and related conditions. This quiz covers key concepts including inflammation of the liver parenchyma and the results of chronic liver disease. Challenge yourself with questions related to liver functionality and outcomes.