2. Pancreatitis

Question 1

Types of pancreatitis

Answer 1

1. Acute pancreatitis

2. Chronic pancreatitis

Question 2

Definition of pancreatitis

Answer 2

Inflammation of the pancreas associated with injury to the exocrine pancreas; ranges from a transient attack to a permanent loss of function

Question 3

Definition of acute pancreatitis

Answer 3

Reversible pancreatic parenchymal injury associated with inflammation

Question 4

Causes of acute pancreatitis

Answer 4

1. Obstruction of pancreatic duct system
   - Cholelithiasis
   - Periampullary neoplasms
   - Pancreas divisum
   - Choledochal cysts
   - Parasites
2. Alcoholism
3. Infections
   - Mumps virus, Ascaris lumbricoides, Clonorchis sinensis
4. Acute ischemia
   - Shock, thrombosis, embolism, vasculitis
5. Drugs
   - Furosemide, azathioprine, estrogens
6. Hyperlipoproteinemia
7. Hypercalcemia
8. Mechanical causes
   - Trauma, iatrogenic
9. Hereditary pancreatitis
   - AD form: trypsinogen mutation rendering trypsin resistant to inactivating cleavage by another trypsin
   - AR form: trypsin inhibitor mutation

I GET SMASHED
Idiopathic 
Gall stones 
Ethanol
Trauma 
Steroids 
Mumps
Autoimmune 
Scorpion venom 
Hyperlipidemia/Hypercalcemia 
ERCP
Drugs (OCT)

Question 5

Pathogenesis of acute pancreatitis

Answer 5

1. Initiating event:
   - Due to causes of pancreatic duct obstruction leading to interstitial edema which impairs blood flow resulting in ischemic damage, & also due to accumulation of lipases causing local fat necrosis
   - Due to causes of direct acinar cell injury, resulting in release of intracellular proenzymes & lysosomal hydrolases, which activates proenzymes
2. Either way, initiating event leads to further acinar cell injury, which results in local activation of pancreatic enzymes, leading to:
   - Interstitial edema & inflammation
   - Proteolysis (proteases)
   - Fat necrosis (lipases, phospholipases)
   - Hemorrhage (elastase)

Question 6

Morphology of acute pancreatitis

Answer 6

1. [Grossly]
   - Hemorrhage & necrosis
   - Fat necrosis of adipose tissue (within pancreas, peripancreatic fat, omentum & mesentery)
   - Fat saponification (when fat necrosis is combined with calcium salt)
   - Chicken broth peritoneal fluid (serous, slightly turbid brown- tinged fluid; due to fat necrosis releasing fat globules into peritoneal fluid)
2. [Histologically]
   - Inflammatory infiltrate
   - Interstitial edema
   - Areas of fat necrosis (adipocytes containing amorphous material due to deposition of calcium salts within them)

Question 7

Clinical features acute pancreatitis

Answer 7

1. Signs & symptoms:
   - Intense, constant abdominal pain, often referred to the upper back or even to the left shoulder
2. Laboratory findings:
   - Raised serum amylase & lipase
   - Conjugated hyperbilirubinemia (if obstruction is common to pancreatic & biliary ducts)
   - Glycosuria (due to damage to endocrine pancreas)
   - Hypocalcemia (due to draining of calcium in fat saponification; poor prognostic sign)

Question 8

Pathological Effects & Complications of acute pancreatitis

Answer 8

1. Systemic organ failure
   - Shock, ARDS, acute renal failure
2. Pancreatic abscess formation
3. Pancreatic pseudocyst formation
   - A pseudocyst has no true epithelial lining, just a focus of necrotic material walled off by fibrous/granulation tissue
   - Cannot be excised, has to be drained
   - May be subsequently infected by gut microbes
   - May lead to chronic pancreatitis
4. Duodenal obstruction

Question 9

Definition of chronic pancreatitis

Answer 9

Inflammation of the pancreas with irreversible destruction of the exocrine parenchyma, fibrosis & in the late stages, destruction of the endocrine parenchyma

Question 10

Causes of chronic pancreatitis

Answer 10

1. Long-term alcohol abuse (most common cause)
2. Long-standing pancreatic duct obstruction
   - Pseudocysts (complication of acute pancreatitis)
   - Calculi
   - Trauma
   - Pancreas divisum
   - Neoplasms
3. Hereditary causes (same as those for acute pancreatitis)
4. Cystic fibrosis
5. Autoimmune (lymphoplasmacytic sclerosing pancreatitis)

Question 11

Pathogenesis of chronic pancreatitis

Answer 11

Progressive destruction of pancreas by repeated flare-ups of mild & subclinical types of acute pancreatitis

Question 12

Morphology of chronic pancreatitis

Answer 12

1. Atrophy of acini
2. Dilated ducts containing protein plugs
3. Interlobular fibrosis & chronic inflammatory infiltrate
4. Calcifications
5. Pseudocysts
6. Remaining surviving islets embedded in a sclerotic background

Question 13

Pathological Effects & Complications of chronic pancreatitis

Answer 13

1. Chronic malabsorption (due to deficiency in exocrine pancreatic enzymes required for digestion of food)
2. Diabetes mellitus (due to loss of islets of Langerhans)