11b. Pancreatitis: Acute and Chronic

Question 1

acute pancreatitis as seen clinically and on path?

Answer 1

clinically: abdominal pain, high amylase and/or lipase
path: acute inflammation of panc, often with necrosis

Below: mild acute

Question 2

mild pancreatitis: appearance on histo?

Answer 2

lobules separated due to edema, some inflammatory cells scattered throughout interstitial area

Question 3

difference between mild and severe acute pancreatitis?

Answer 3

bottom line: difference is NECROSIS/HEMOR mild: edema with inflammatory infiltrate. NO necrosis severe: extensive necrosis of parenchyma and fat, hemorrhage due to leaky blood vessels

Question 4

besides necrosis of the pancreatic parenchyma and fat, what else might severe acute pancreatitis cause?

Answer 4

fat necrosis extensively spread throughout abdomen. due to release of pancreatic lipase

Question 5

what structures of the pancreas succumb to necrosis and inflammation earliest in severe acute pancreatitis?

Answer 5

acinar tissue first, then ducts, then islets fat will also necrose.

Question 6

what is the course of severe acute pancreatitis?

Answer 6

focal (causes focal scarring) then multifocal (patchy scarring) then extensive (SIRS, death, or pseudocysts and abscesses)

Question 7

define a pseudocyst in the context of acute pancreatitis

Answer 7

walled-off collection of fluid or liquefied tissue. progressively fibrotic. can be small or large, and can involved tissue adjacent to the pancreas

Question 8

define an abscess in the context of acute pancreatitis. how to diagnose?

Answer 8

necrotic tissue or pseudocyst that has become infected. dx: identify microbe in aspirated liquid

Question 9

very briefly, what characterizes chronic pancreatitis?

Answer 9

-fibrosis and atrophy, resulting from bouts of inflammation -can be focal, multifocal or diffuse -may see dilated main duct, stones in duct

Question 10

general causes of chronic pancreatitis?

Answer 10

-alcoholism (repeated acute -> chronic) -cystic fibrosis (due to duct obstruction) -autoimmune -hereditary (repeated acute -> chronic) -progression from acute to chronic via repeated episodes

Question 11

histologically, what is the biggest difference between acute and chronic pancreatitis?

Answer 11

chronic specimens have replaced the areas of necrosis with fibrosis. still may be some inflammation and edema, but definitely will see fibrosis.

Question 12

what are complications of chronic pancreatitis?

Answer 12

-dietary malabsorption -diabetes -incr risk of pancreatic carcinoma

Question 13

Two biggest causes of pancreatitis in US?

Answer 13

alcohol, gallstones

Question 14

Besides alcohol and gallstones, causes of pancreatitis?

Answer 14

drug toxicity, viral infection (mumps, CMV), trauma (steering wheel to the gut), genetic, autoimmune dz

Question 15

Pathogenesis of pancreatitis? two pathways

Answer 15

-injury to acinar cells. inappropriate release of panc enzymes leading to autodigestion and inflammation -ductal obstruction. increased pressure, interstitial leakage, activation of pancreatic enzymes

Question 16

Typically enterokinase in the duodenal brush border activates trypsin and thus triggers the activation cascade for pancreatic enzymes. What else can activate trypsin? (comes from leukocytes)

Answer 16

Cathepsin B can trigger a huge cascade which ends in autodigestion of the pancreas, fat necrosis, and systemic shock

Question 17

gallstones: cause acute or chronic pancreatitis or both?

Answer 17

acute. NOT a major cause of chronic pancreatitis

Question 18

hereditary cause of pancreatitis: due to mutation in what gene?

Answer 18

mutant trypsinogen gene. normally has a site to prevent its own activation (has ability to auto-digest if needed). the mutation turns off this ability -> trypsin resists inactivation, persists longer, causes damage, pt is predisposed to pancreatitis.

Question 19

pts with hereditary familial pancreatitis: what is the incidence of pancreatic carcinoma in pts with this mutation?

Answer 19

40% have pancreatic carcinoma by 70y

Question 20

how does cystic fibrosis cause chronic pancreatitis?

Answer 20

the CFTR gene causes a defect in epithelial cell electrolyte transport. cannot adequately hydrate mucus. viscous material collects in ducts. leads to ductal obstruction -> chronic pancreatitis

Question 21

CF patients with pancreatitis: characteristic change seen on histo?

Answer 21

diffuse fibrosis, dilated ducts, there is mucous inside the ducts

Question 22

autoimmune pancreatitis (AIP): how will the pancreas appear grossly? what has it historically been mistaken for?

Answer 22

the pancreas has a mass on the head of the pancreas, visible with imaging. historically this has been mistaken for cancer and the pancreas removed.

Question 23

how will a patient with AIP present? what treatment should work for them?

Answer 23

presents with jaundice (maybe other things; ppt was sparse on this) tx = steroids

Question 24

how does AIP look on histology?

Answer 24

path diagnosis is chronic and acute pancreatitis, with fibrosis and atrophy. periductal inflammation, lumens are being squeezed closed. fibrosis and inflammation are focused on ducts.

Question 25

what immune components are involved in AIP? Labs?

Answer 25

AIP Type 1 is associated with IgG4-related diseases and involvement of other nearby organs. labs will have elevated serum IgG4 or autoantibodies. Note that there is also AIP Type 2: associated with IBD.

Question 26

how does alcoholism cause acute pancreatitis?

Answer 26

thought that it’s a direct toxic effect of alcohol or one of its metabolites -> altered lipid metabolism -> oxidative stress -> free radicals