Histo: Diseases of the Pancreas and Gallbladder Pt.1

Question 1

What are the main components of the exocrine part of the pancreas?

Answer 1

Acini and ducts

Question 2

What is the endocrine component of the pancreas called?

Answer 2

Islets of Langerhans

Question 3

Define acute pancreatitis.

Answer 3

Acute inflammation of the pancreas caused by aberrant release of pancreatic enzymes

Question 4

List some causes of acute pancreatitis.

Answer 4

Duct obstruction
- Gallstone (50%)
- Trauma
- Tumours

Metabolic/toxic
- Alcohol (33%)
- Drugs (e.g. thiazides)
- Hypercalcaemia
- Hyperlipidaemia

Ischaemia
- Shock
- Hypothermia

Infection/inflammation
- Mumps
- Autoimmune

Idiopathic (15%)

NOTE: gallstones + alcohol are KEY

Question 5

What is the basic common pathogenesis of both gallstone and alcohol-induced acute pancreatitis?

Answer 5

Duct obstruction

The rest of the etiologies cause acute pancreatitis via direct acinar injury

Question 6

Describe how gallstones causes acute pancreatitis

Answer 6

• Gallstones can obstruct the bile ducts distal to where the common bile ducts and pancreatic ducts join
• This leads to the reflux bile up the pancreatic ducts which can damage the acini
• Digestive proenzymes are released which then become activated

Question 7

Describe how alcohol can cause acute pancreatitis.

Answer 7

It leads to spasm/oedema of the sphincter of Oddi and the increasing the viscosity of pancreatic secretions. Both of these cause duct obstruction.

Question 8

Describe the three main patterns of injury in acute pancreatitis

Answer 8

• Periductal - necrosis of acinar cells near ducts (usually secondary to obstruction)
• Perilobular - necrosis at the edges of the lobules (usually due to poor blood supply)
• Panlobular - develops as periductal or perilobular inflammation worsens

Question 9

Outline the pathway of inflammation in acute pancreatitis.

Answer 9

Activated enzymes → acinar necrosis → release of more enzymes

Question 10

What is saponification?

Answer 10

• Lipases break down fats to release free fatty acids
• Calcium binds to the free fatty acids forming soaps
  (yellow-white foci)

Question 11

List some complications of acute pancreatitis.

Answer 11

Local:

• Pseudocyst formation
• Abscesses

Systemic:

• Sepsis
• ARDS
• DIC
• Shock
• Hypoglycaemia
• Hypocalcaemia

Question 12

Define pseudocyst.

Answer 12

• A collection of fluid lined by fibrous tissue (no epithelial lining)
• They are rich in pancreatic enzymes and necrotic material

They may resolve, compress adjacent structures, become infected, or perforate

More commonly associated with chronic pancreatitis but can occur with acute

Question 13

List some causes of chronic pancreatitis.

Answer 13

Metabolic/Toxic:

• Alcohol (80%)
• Haemochromatosis

Duct obstruction:

• Gallstones
• Abnormal anatomy
• Cystic fibrosis

Autoimmune

Tumours

Idiopathic

Question 14

Outline the pattern of injury in chronic pancreatitis.

Answer 14

• Chronic inflammation with parenchymal fibrosis and loss of parenchyma
• There will be duct strictures with calcified stones with secondary dilatations

Question 15

Describe the difference between WBCs seen in acute vs chronic pancreatitis

Answer 15

• Acute - neutrophils
• Chronic - lymphocytes

Question 16

List some complications of chronic pancreatitis.

Answer 16

• Malabsorption
• Diabetes mellitus
• Pseudocysts
• Pancreatic carcinoma

Question 17

What radiographic feature is diagnostic of chronic pancreatits?

Answer 17

Visible pancreatic calcifications on AXR

Question 18

What is the cytological feature is characteristic of autoimmune pancreatitis?

Answer 18

Large numbers of IgG4 positive plasma cells typically found around the ducts

Question 19

How is autoimmune pancreatitis treated?

Answer 19

Steroids - usually responds well

Question 20

Name 3 categories of pancreatic neoplasms

Answer 20

• Carcinomas
• Cystic neoplasm (cystadenomas)
• Neuroendocrine tumours (islet cell tumours)