Week 2: Pathology of exocrine pancreas

Question 1

Ectopic pancreatic tissue

Answer 1

• congenital anomaly
• descending order of frequency: stomach, duodenum, jejunum, mocked diverticula, ileum
• gross: submucosal mass
• micro: disorganized pancreatic acini, ducts, islet cells, muscle, fibrosis

Question 2

Maldevelopment of the pancreas

Answer 2

1. agenesis: incompatible with life
2. pancreas divisum: most common clinically significant. predisposes to chronic pancreatitis
3. Annular pancreas: duodenal obstruction
4. Congenital cysts: usually benign

Question 3

Pathology of acute pancreatitis

Answer 3

1. widespread necrosis: proteolytic destruction of tissue.
   - Fat necrosis: chalky white foci in and around pancreas.
2. hemorrhage: necrosis of blood vessels
3. calcification
4. acute inflammatory reaction
5. pancreatic pseudocyst formation

Question 4

pathology of Chronic pancreatitis

Answer 4

1. fibrosis and atrophy of acini
2. diffuse changes.
3. pancreatic ducts show multiple areas of stenosis with irregular dilation distally.
4. relatively spared islets till late stage
5. pancreatic pseudocyst formation
6. chronic inflammation

Question 5

Autoimmune pancreatitis

Answer 5

• lymphoplasmacytic infiltrate
• IgG4 positive plasma cells
• can mimic lymphoma under microscope
• responds to steroids

Question 6

pathology of pancreatic pseduocyst

Answer 6

• most common type of cysts, complication of pancreatitis
• usually solitary, unilocular cysts of variable case
• lined by wall composed of macrophages, collagen, inflamed granulation tissue. No epithelial lining

Question 7

Congenital cysts

Answer 7

• rare
• associated with other congenital diseases: polycystic renal disease, congenital hepatic fibrosis, VHL disease
• true cysts, lined by ductal type cuboidal epithelium

Question 8

Serous cystadenoma

Answer 8

• microcystic, glycogen rich
• rare, incidental findings
• benign usually
• multilocular, cuboidal serous epithelial lining, rich in cytoplasmic glycogen
• females: males 2:1

Question 9

Mucinous cystic neoplasms

Answer 9

• mostly women, more common than serous cyst adenoma
• solitary unilocular, large
• tall, columnar mucinous epithelial lining
• benign, borderline, malignant
• borderline: atypic but not invasion
• cystadenocarcinoma: atypia, stratification of lining cells, invasion, like low grade malignancy

Question 10

Intraductal papillary mucinous neoplasms

Answer 10

• arising in main pancreatic duct
• head of pancreas
• males
• benign, borderline, and malignant

Question 11

Epidemiology of pancreatic carcinoma (most commonly ductal adenocarcinoma) and etiology

Answer 11

-more men than women, blacks than whites, after age 50
-4th leading cause of cancer deaths in US
-etiology:
gene mutations: Kras, tumor suppressor gene p16, SMAD4, p53. familial pancreatitis PRSS1
-cigarette smokers have increased risk

Question 12

Pathology of pancreatic carcinoma

Answer 12

• head> body > tail >diffuse
• gross: firm, infiltrative mass, distal obstruction. =
• 99% from ducts and rest from acini
• carcinomas of head tend to obstruct common build duct early on
• tumors in tail present late stage and are large
• micro: moderately to poorly differentiated adenocarcinoma. early invasive and desmoplastic (growth of fibrous/CT) reaction in stroma. Storm fibrosis. Anapestic cuboidal to columnar epithelial cells.

Question 13

Spread of pancreatic ductal adenocarcinoma.

Answer 13

• perineural spread typical
• early lymphatic spread
• early blood stream spread, commonly to liver

Question 14

Treatment and prognosis of pancreatic carcinoma

Answer 14

• many inoperable at presentation
• small carcinomas treated with Whipple procedure (pancreaticoduodenectomy)
• Chemo and radiation ineffective
• poor prognosis