153b - Pathology of Gallbladder and BIliary Tract

Question 1

List 5 consequences of cholestasis

(1 intestinal, 4 extra-intestinal)

Answer 1

• Fat malabsorption
  
  • -> Decreased ADEK absorption
• Retention of bile acids -> itching
• High serum bilirubin -> Jaundice
• High serum lipids -> xanthomas
• Hepatic accumulation of copper, bile acids, etc -> liver damage

Question 2

Which antibody is diagnostic of PBC?

Answer 2

Anti-mitochondrial antibody

Question 3

What conditions predispose to black pigment gallstones stones?

Answer 3

Chronic hemolysis

(ex: Sickle Cell Disease)

Question 4

What is the most significant risk factor for gallbladder carcinoma?

Answer 4

Gallstone

Question 5

How can you differentiate between cholecystitis and choledocholithiasis on presentation?

Answer 5

• Cholecystitis
  
  • Fever, RUQ pain
  • Leukocytosis (due to inflammation of the gallbladder)
• Choledocholithiasis
  
  • Nausea/vomiting
  • Jaundice
  • These patients will probably be in a worse state

Also, cholecystitis is more common than choledocholithiasis

Question 6

Describe the typical presentation of PSC

Answer 6

• Young man
• Diarrhea/bloody stools
• Jaundice
• Fatigue
• Itching
• Elevated Alk-phos, bilirubin
• Normal AST/ALT

Question 7

Describe the typical presentation of PBC

Answer 7

• Middle-aged women
• Xanthoma
• Puritis
• Jaundice

Generally, not supper ill on presentation

Question 8

Describe the metabolism and excretion of bilirubin

Answer 8

Bilirubin is formed from the breakdown of heme

• Heme breakdown -> Biliverdin
• BIliverdin is bound to albumin in the blood
• > unconjugated Bilirubin
• Unconjugated bilirubin is conjugated by UDP-GT -> conjugated bilirubin
• Congugated bilirubin is part of the bile; dumped into the GI tract and excreted
  
  • Bacteria may de-conjugate the bilirubin -> urobilinogen
  • This can be reabsorbed and excreted in the urine

Question 9

Where is bilirubin conjugated?

By what enzyme?

Answer 9

Liver (macrophages specifically)

UDP Glucanosyltransferase (UDP-GT)

Question 10

Primary sclerosising cholangitis increases the risk of which 2 cancers?

Answer 10

Cholangiocarcinoma

Colorectal carcinoma

Question 11

If a patient has elevated alkaline-phosphatase, what lab finding would confirm a biliary duct/tree problem?

Answer 11

Elevated GGT

[This is to set the difference b/w bone disease-related Alk Phos increases]

Question 12

List 2 autoimmune cholangiopathies

How can you differeniate them?

Answer 12

• Primary biliary cholangitis (PBC)
  
  • Intrahepatic
  • (+) Anti-mitochondrial antibody
  • More common in middle-aged women
• Primary sclerosing cholangitis (PSC)
  
  • Extrahepatic
  • (+) P-ANCA
  • More common in younger men with Ulcerative Colitis
  • “Onion skin fibrosis” around bile ducts