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Liver Pathology
Pathology Lecture 3-4
Question | Answer |
---|---|
What are the main functions of the liver? ** | CHO metabolism, production of albumin, fibrinogen, and coag factors, metabolism of drugs and toxins, and congjugation of bile |
The yellow tinting of organs and viscera is known as: ** | Jaundice |
What are the four causes of hyperbilirubinemia? ** | Intravascular hemolysis, extravascular hemolysis, severe hepatic disease, and cholestasis |
What area of the liver is most sensitive to hypoxia and biliary obstruction ** | Centrilobular |
In what tissues is jaundice most evident? | Elastin rich tissues such as the aorta and sclera |
Name the process: Erythrocytes destroyed IN CIRCULATION. Hemoglobin is removed by the liver or excreted by the kidney. Common causes include bacterial, protozoal, oxidants, venoms, incompatible transfusions, etc. | Intravascular hemolysis |
Name the process: Erythrocytes sequestered in the liver and spleen and phagocytized or lysed. Hg is catabolized at the stie of destruction. Causes include parasites, bacteria, autoimmune, fragmentation, etc. | Extravascular hemolysis |
How does severe hepatic disease cause icterus? | severe acute or chronic loss of hepatocytes results in decreased bilirubin uptake by hepatocytes |
How does cholestasis cause icterus? | Bile flow out of the liver is obstructed either intrahepatically or extrahepatically |
What disease process do you think of with a grossly small liver, lobular atrophy, reduplication of arterioles and absence or atrophy of portal veins and hepatic encephalopathy? ** | Congenital Portosystemic Shunts |
Differentiate intra and extra hepatic portosystemic shunts: | Intra: failure of ductus venosus to close --- large breeds susceptible Extra: Portal v. to azygous, portal v. to abdominal vena cava (both in small dogs) or L gastric vein to abdominal vena cava in cats... or atresia of portal vein --> in multiple shunt |
What does hypertension due to resistance of portal blood flow commonly cause? ** | acquired portosystemic shunts --- creats collateral vascular channels |
What disease process often causes passive congestion characterized by enlarged liver with an enhanced lobular or reticular pattern commonly called "nutmeg liver" ** | Right-sided heart failure |
What may cause occlusion of the pulmonary artery and right heart leadin gto an engorged liver and severe passive congestion? | Vena Caval Syndrome -- Dirofilaria immitis |
What is caused by a direct communication btw the hepatic artery and branches of the portal vein? | Arterioportal shunts (anstomoses) |
What is caused by a thickening of the central vein by fibrous connective tissues leading to passive hepatic congestion and heaptic failure. May be linked to pyrrolizide alkaloid or aflatoxin injury. Common in cheetahs. | Hepatic Veno-occlusive Disease |
What is caused by dilation of sinusoids in areas where hepatocytes have been lost. May appear as multiple dark blue/red foci on the capsular surface. | Telangiectasis |
Why is insult due to infarction rare in the liver? ** | Duel blood supply |
Which vessel is responsible for 70% of the liver's blood supply? ** | Portal Vein, 30% - Hepatic Artery |
What 3 conditions could lead to loss of blood supply in the liver? ** | Sepsis, Thromboembolism, DIC |
What is due to acquired metabolic disturbances that cause accumulation of lipid or glycogen in the cytoplasm of hepatocytes? | Hepatocellular degeneration |
_____________ occurs when triglyceride accumulation within hepatocytes exceeds the rate of metabolic degradation or the release as lipoproteins. | Hepatic Lipidosis |
What 6 mechanisms may contribute to hepatic lipidosis? | 1. Excessive dietary fat 2. Abnormal hepatocyte fxn 3. Excess CHO intake 4. Increased esterification of fatty acids --> triglycerides 5. Dec. apoprotein synth. 6. Imp. secretion of lipoprotein |
Associated with anorexia in obese cats, idiopathic hepatic lipidosis is known as: ** | Feline fatty liver syndrome |
Endocrine related hepatic lipidosis is the result of ____ fat mobilization and ____ utilization of lipids by injured hepatocytes | increased, decreased |
Excessive intrahepatic accumulation of ______ may occur with Diabetes Mellitus. ** | Glycogen |
How do glucocorticoids induce hepatocellular degeneration? ** | excessive amounts cause swelling of hepatocytes due to accumulation of glycogen |
How does glucocorticoid-induced hepatocelleular deg. look grossly and microscopically? ** | Gross: enlarged and pale Micro: hepatocytes in midzonal area will be swollen up to 10x normal size and contain vacuoles that are PAS positive |
What are the 3 types of amyloidosis that affect the liver? | 1. AL, Amyloid light chain "primary amyloidosis" 2. SAA, Serum amyloid-associated, more common "secondary" 3. Inherited or familial (sharpei dogs,abyssinian and siamese cats) |
What does hepatic amyloidosis look like grossly and microscopically? ** | Gross: pale fragile liver, rupture and exsanguination may occur Micro: protein is birefringent with characteristic apple green appearance in congo red stain |
What breeds are highly susceptible to hereditary copper toxicosis? ** | Bedlington terrier and West highland white terriers |
When is copper accumulation more commonly observed and what breeds does this commonly occur in? | Chronic cholestatic liver disease, skye terries, damolations, and dobies w/ chronic liver disease |
Increased storage of iron within hepatocytes and kupffer cells associated with hepatic disfunction | Hemochromatosis |
Systemic disease characterized by abundant intracytoplasmic hemosiderin in variety of tissues and hepatocytes | Hemosiderosis |
_____ is more a more serious condition and may be accompanied by fibrosis | Hemosiderosis |
The cirrhotic liver is characterized by: ** | 1. Loss of normal hepatic architecture 2. Fibrosis 3. Biliary duct hyperplasia |
Portal hypertension may lead to: ** | 1. vascular anastomoses btw portal v. and systemic vasculature 2. venous shunts btw central v. and portal v. 3. arteriovenous shunts btw hepatic a and central v. |
Diffuse massive liver damage is often characteristic of: ** | Tyzzer's disease in horses or Blue-Green Algae hepatotoxicity |
Periportal liver damage is often due to: ** | toxins |
Midzonal liver damage is often due to: ** | Corticosteroids or other toxins |
Centrilobular hepatic damage is often due to: ** | hypoxia, congestion, toxins (CCl4) |
Random, multifocal hepatic damage is often due to: ** | hematogenous spread |
Besides bilirubin what else does bile contain? | Water, bile acids, cholesterol, inorganic ions, and other constituents |
Bile provides: | 1. bile acids for digestion of dietary fats and fat sol. vitamins 2. excretory route for metabolites and drugs 3. buffers to neutralize acid pH of ingesta |
Bile acids reabsorbed from the intestine and re-secreted into the bile is known as: | enterohepatic circulation of bile acids |
Inflammation of the gall bladder: | Cholecystitis |
What may cause cholecystitis/cholangitis? ** | 1. gallbladder mucoceles 2. choleliths 3. biliary tract neoplasia 4. pancreatic inflammation 5. immunosupression from DM or hyperadrenocorticism |
What is a viral cause of cholecystitis in dogs? ** | Adenovirus Type 1 (uncommon) |
What does cystic mucinous hyperplasia of the gallbladder look like? ** | Gross: grey-white mucosa with a sponge-like consistency The mucosa is expanded by polypoid masses, cystic, and papillary projections. |
Who do we commonly see congenital biliary cysts in? ** | Adult cats and Cairn terriers |
Inflammation of the liver parenchyma: | Hepatitis |
What infectious cause of hepatitis may be accompanies by tonsil and LN enlargement and corneal edema termed "blue eye" ** | Canine Adenovirus type 1 |
What does infection hepatitis due to adenovirus look like? ** | diffuse petechiaal and ecchymotic hemorrhage, accumulation of clear fluid in peritoneal cavity, fibrin strands on liver surface, enlarged friable liver w/ small foci of hepatocellular necrosis on central lobular areas |
This virus produces multifocal necrosis in neonatal pups but foci of necrosis are more consistently present in the kidneys, lungs, and spleen. | Herpesvirus |
Multifocal small pale nodules and pyogranulomatous vasculitis can be characteristic of: | FIP --- nodules follow vessels |
Tyzzer's disease = | Clostridium piliformis |
Who does tyzzer's dz affect and what does it look like? | Young or immunocompromised Gross: enlargement w/ random foci of necrosis with enlarged edematous hemorrhagic abdominal LN Micro: large foci of necrosis with Warthin Starry (Steiner stain) |
What other infectious disease causes centriloublar ischemic injury due to intravascular hemolytic anemia | Leptospira grippotyphosa |
What zoonotic bacterium may cause multifocal necrosis and microabcesses that are visible grossly? | Tularemia (Francisella tularensis) |
What systemic dz causes multifocal necrotizing hepatitis in combination w/ viral dz | Toxoplasmosis, often w/ FIP, FeLV, or FIV |
What breeds are predisposed to chronic hepatitis? | Female dobermans, male cocker spaniels |
Disease with ALT approaching 18x the upper limit, slow and insidious with CS appearing late in disease progression | Chronic Hepatitis of Dogs |
Predominate finding is macrophages, etiologies include bacteria, fungi, and parasites | Granulomatous hepatitis |
Observed in middle-old aged cats, usually secondary to ascending biliary infection Gross: jaundice Micro: neuts and lymphocytes and plasma cells in bile duct | Acute or chronic cholangitis and cholangiohepatitis of cats |
Inflammation of liver with jaundice and hepatomegaly, characterized by lymphocytes, Often discovered in young cats who may not appear ill. | Lymphocytic cholangitis of cats |
Clinical signs and Tx of lymphocytic cholangitis of cats | CS: may ppear healthy, lymphoneia, increased liver enzymes and bilea cids Tx: corticosteroids |
Mechanism of toxic liver disease: | ingested toxins absorbed in GI tract, then transported directly to liver via portal vein. Secondly, processes in liver for elimination Lipophilic exogenous chemicals cross cell membranes of skin, lungs, or digestive tract |
Intrinsic toxins affect ______ hepatocytes | periacinar |
Ex of intrinsic toxins | Acetaminophen |
Idiosyncratic toxins may involve ______ mechanisms | immune mediated |
Ex of idiosyncratic toxins | Trimethoprim-sulfa, Diazepam, Carprofen |
Hepatocellular necrosis pattern | Zonal or Panlobular --- cause: acetaminophen, halthane |
Toxic hepatitis pattern | Diffuse or multifocal (phenytoin, sulfonamide, isoniazid) |
What toxin causes zonal or massive hepatic necrosis and hemorrhagic gastroenteritis? ** | Blue-green algae: microcystis, aphanizomenon |
Name 3 additional liver toxins: | Sago Palm, Aflatoxin, Mushrooms (Amanita phalloides) |
What are the 4 primary hepatic tumors in dogs in order of prevalence | Hepatocellular carcinoma, hepatocellular adenoma, hepatic hemangiosarcoma, biliary carcinoma |
What are the 3 primary hepatic tumors of cats in order of prevalence | Biliary carcinoma, hepatocellular carcinoma, hepatic hemangiosarcoma |