Liver Document - Diagnostics

What is liver cytology helpful for diagnosing?

neoplasias that exfoliate well, some infectious causes, metabolic changes, amyloid

What neoplasias can be diagnosed via liver cytology?

neoplasias that exfoliate well - lymphoma, histiocytic sarcoma, carcinoma and those that are poorly differentiated

True or False? Liver cytology can be used to assess fibrosis and inflammation.

False. Liver cytology is NOT accurate for assessing fibrosis or inflammation.

For many inflammatory or fibrotic liver disease what is the best way to get a biopsy?

• 15 portal riads, large cup or wedge biopsy

• full anesthesai recommended

• assess coagulation prior, PTT >2x normal is contraindication

• fasted animal

What is liver cytology most useful for diagnosing?

Cancers that exfoliate well (lymphoma, histiocytic sarcoma, carcinoma) and poorly differentiated tumors.

Why is cytology less accurate for fibrosis and inflammation?

Because cytology samples lack architecture — it only collects individual cells, not tissue structure.

What are common cytologic features of well-differentiated hepatocellular carcinoma?

Altered hepatocellular arrangement, absence of lipofuscin granules, variable cell size and nuclear atypia.

What cytologic feature can help differentiate benign vacuolar changes?

Distinct lipid vacuolation indicates lipid accumulation (as in hepatic lipidosis); rarefaction may indicate water or glycogen accumulation.

What cytologic changes occur with steroid hepatopathy?

Glycogen accumulation causing vacuolar change (rarefaction) due to endogenous or exogenous steroids.

What conditions cause lipid accumulation in hepatocytes?

Diabetes mellitus, hepatic lipidosis, and metabolic disorders increasing lipid mobilization.

What infectious agents can be identified on liver cytology?

Bacteria, fungi, algae, trematodes, and protozoa.

What breed predisposition is important to remember when aspirating amyloidotic livers?

Shar Peis and Abyssinian cats — because aspiration can cause severe hemorrhage.

Concept: Cytology provides ____, not architectural. Biopsy provides_____ — use both when possible.

cellular information, tissue organization

What is the main purpose of a liver biopsy?

To differentiate between types of liver disease (inflammatory, neoplastic, vascular, fibrotic, metabolic).

How many portal triads are ideal for evaluating inflammatory/fibrotic diseases?

Approximately 15 portal triads are needed for accurate assessment.

Why must coagulation status be checked before biopsy?

Severe hepatic dysfunction or cholestasis can cause prolonged PT/PTT, increasing hemorrhage risk.

What PTT prolongation is a contraindication for biopsy?

PTT > 2× normal.

What is the recommended pretreatment for cats with prolonged clotting times and biliary disease?

SC vitamin K, 3 doses every 12 hours before biopsy.

What conditions can be diagnosed with fine-needle aspirate (FNA)?

Hepatic lipidosis, vacuolar hepatopathy, lymphoma, and many primary/metastatic neoplasms.

Why must FNA results be interpreted cautiously in hepatic lipidosis?

Because lipidosis may coexist with other diseases (chronic hepatitis, cholangitis).

What is the advantage of Tru-Cut biopsy over FNA?

Preserves tissue architecture, allowing for evaluation of fibrosis, necrosis, and vascular structure.

What gauge needles are typically used for Tru-Cut biopsy?

14 gauge for medium/large dogs; 16 gauge for small dogs and cats.

How many samples are recommended for reliable Tru-Cut biopsy results?

2–3 unfragmented 1–2 cm samples from different lobes.

What region of a hepatic mass should be sampled?

Both the periphery and the center (since centers may be necrotic).

What artifact can occur with subcapsular sampling?

Subcapsular fibrosis — a nonpathologic finding that may lead to misdiagnosis.

Why should biopsies not be taken adjacent to the gallbladder?

Possible artifact from inflammation or fibrosis in that region.

What methods can assess copper or metal quantification in biopsy samples?

Fresh tissue for metal quantification, or deparaffinized histologic samples (e.g., CSU, Cornell).

What does neutrophilic inflammation in biopsy indicate?

Possible bacterial infection; warrants culture or FISH.

What does granulomatous inflammation in a liver biopsy suggest?

Immune-mediated, bacterial, viral, or fungal etiology.

What does lymphoplasmacytic inflammation in a liver biopsy indicate?

Usually immune-mediated (e.g., chronic hepatitis).

Why should both liver and bile be cultured in cats?

Biliary obstruction often implies bacterial infection.

What is the normal liver position relative to the ribs on radiographs?

Should not extend beyond the last rib.

What does a vertical gastric axis indicate on radiographs?

Possible microhepatica (e.g., congenital shunt, cirrhosis).

What are the common causes of focal hepatic enlargement?

Neoplasia, granuloma, cysts, abscesses, regenerative nodules, arterioportal fistulas.

What causes generalized hepatic enlargement?

Neoplasia, lipidosis, glycogen accumulation, chronic hepatitis, amyloidosis, and acute hepatitis.

What mineralized hepatic findings may be seen on radiographs?

Choleliths or choledocholithiasis; granulomas; abscesses.

What can cause gas opacities in the liver?

Hepatic abscess, emphysematous cholecystitis, or biliary obstruction.

What is the sonographic appearance of acute hepatitis?

Generalized hypoechoic parenchyma.

What is the sonographic appearance of hepatic lipidosis or fibrosis?

Generalized hyperechoic liver.

What diseases can cause a hyperechoic liver on ultrasound?

Glycogen accumulation, lipidosis, fibrosis, amyloidosis, and cholangiocarcinoma.

What do hypoechoic focal lesions suggest?

Abscesses, lymphoma, or acute inflammation.

What imaging finding suggests chronic liver disease with shunts?

Small liver with increased echogenicity and acquired portosystemic collaterals.

What ultrasound finding supports congenital portosystemic shunt?

Decreased portal vein-to-aorta ratio, reversed portal flow, visible shunting vessels.

What is CT imaging especially useful for in hepatic disease?

Identifying portosystemic shunts, liver masses, and 3D vascular mapping.

What imaging modality provides the best sensitivity for hepatic masses?

Computed tomography (CT), especially dual/triple-phase studies.

Why might MRI be used less often in veterinary liver imaging?

It’s more expensive and has longer acquisition times.

When is gallbladder aspiration (cholecystocentesis) indicated?

In suspected infectious biliary disease.

What is the risk of aspirating a diseased gallbladder wall?

Rupture and bile peritonitis.

Why should aspiration be avoided if biliary ducts appear distended?

Suggests obstruction, increasing rupture risk.

What can reduce leakage risk during gallbladder aspiration?

Aspirating through liver parenchyma, which compresses and seals the puncture site.

What additional benefit does gallbladder aspiration have in intoxications?

Can help remove toxins undergoing enterohepatic circulation, reducing ongoing liver injury.

What samples should be submitted for culture after gallbladder aspiration?

Aerobic and anaerobic bacterial cultures.