Pathology of the Biliary Tree and Pancreas Flashcards
What 4 components make up the micelles found in normal bile?
Cholesterol
Phospholipid
bile salts
bilirubin
the four of these join together to form spherical shaped lipid molecules (micelles)
Where is bile normally stored and how is it released into the duodenum?
- Stored and concentrated in Gall Bladder
- Released by Cholecystokinin (CCK)
- flows through common bile duct and Ampulla of Vater into 2nd part of duodenum
What causes cholesterol gallstones to form?
- an imbalance between the ratio of cholesterol to bile salts
=> disrupting micelle formation
=> cholesterol crystallises on the micelle surface
What puts patients at risk of high cholesterol and cholesterol gallstone formation?
- female
- obesity
- diabetes
- genetic
How do cholesterol gallstones and pigment gallstones differ in appearance?
Cholesterol stones = Pale and larger in size
Pigment stones = dark and smaller
When do pigment gallstones occur?
- When there is excess bilirubin present that cant be dissolved in bile salts
- e.g. in haemolytic anaemias or conditions where excess haemolysis takes place
Most gallstones are a mixture of cholesterol and pigment. TRUE/FALSE?
TRUE
- Pure cholesterol and pure pigment stones do occur though
- Calcium carbonate stones also occur < 10%
Gallstones can cause a variety of complications. Give examples of these.
IN GALL BLADDER
- Acute/Chronic Cholecystitis
- Mucocoele
- Carcinoma
IN LIVER
- Ascending Cholangitis
IN BILE DUCTS
- Obstructive Jaundice
- Gallstone Ileus
IN PANCREAS
- Acute/Chronic Pancreatitis
What happens in acute cholecystitis?
- Gallstones obstruct outflow of bile
- Initially sterile, then becomes infected
- May cause empyema, rupture, peritonitis
- Causes intense adhesions within 2-3 days
How does acute cholecystitis appear on histology?
- Acute inflammation indicated by neutrophils
What happens in chronic cholecystitis? How does this look on histology?
- Galbladder wall is thickened but not distended
- Chronic inflammation and Rokitansky-Aschoff sinuses
What type of carcinoma can gallstones cause to occur in the gallbladder?
Adenocarcinoma
- Usually has local invasion of liver
- Poor prognosis
What is cholangiocarcinoma and what conditions is this associated with?
- Rare cancer of the BILE DUCTS
- Associated with UC and PSC
How does cholangiocarcinoma usually present?
- obstructive jaundice
HOw does cholangiocarcinoma look on histology?
- Densely packed small glands (as its an adenocarcinoma)
- in a fibrous stroma
How do patients usually present with acute pancreatitis?
- Adults
- Sudden onset severe abdominal pain
- Patients may be severely shocked
- Elevated serum amylase
What are the main causes of pancreatitis?
Acronym GET SMASHED
Gallstones
Ethanol (alcohol)
Trauma
Shock Mumps Autoimmune Scorpion Hyperparathyroid ERCP Drugs (e.g. steroids)
How is pancreatitis thought to occur pathologically?
- Bile reflux / duct obstruction due to stone
=> damage sphincter of Oddi
=> cause pancreatic duct epithelial injury - Loss of protective barrier allows autodigestion of pancreatic acini
- Release of lytic enzymes (proteases and lipases) which break pancreas down
How do proteases and lipases break the pancreas down?
Proteases cause tissue destruction and haemorrhage
Lipases cause Intra- and peripancreatic fat necrosis
What complications can arise from acute pancreatitis?
- Death
- Shock
- Pseudocyst formation
- Abscess formation
- Hypocalcemia
- Hyperglycemia
What is thought to cause chronic pancreatitis?
Alcohol Gallstones Cystic fibrosis Hyperparathyroidism Familial
What happens to the pancreas pathologically in chronic pancreatitis?
- Exocrine pancreas is replaced by chronic inflammation and fibrosis
What type of carcinoma can be found in the pancreas?
Adenocarcinoma (due to presence of glands)
Pancreatic carcinoma is associated with what other conditions?
- smoking
- diabetes
- familial pancreatitis
