Pancreas & Peritoneal Cavity Pathology - Nelson

Question 1

Define pancreatic agenesis.

Answer 1

absence of the pancreas

Question 2

Define pancreas divisum.

Answer 2

failure of fusion of the fetal dorsal and ventral pancreatic ducts

Question 3

Define annular pancreas.

Answer 3

band-like ring of normal pancreatic tissue that completely encircles the second portion of the duodenum

Question 4

Define ectopic pancreas.

Answer 4

pancreatic tissue found in the stomach, duodenum, jejunum, Meckel’s diverticulum, and ileum.

These tissue nests are usually small (millimeters in size), are often located in the submucosa, and are typically incidental findings.

Question 5

How is fatty tissue and pancreatic parenchyma injured in acute pancreatitis?

Answer 5

autodigestion of the pancreatic tissue by inappropriately released, activated pancreatic enzymes

_{(microvascular leakage causing edema, necrosis of fat by lipolytic enzymes, acute inflammation, proteolytic destruction of pancreatic parenchyma, and destruction of blood vessels and subsequent interstitial hemorrhage)}

Question 6

What is the difference between the gross and microscopic findings of acute hemorrhagic necrotizing pancreatitis versus long-standing chronic pancreatitis?

Answer 6

• Acute
  
  • edema, necrosis of fat by lipolytic enzymes, acute inflammation, proteolytic destruction of pancreatic parenchyma, and destruction of blood vessels and subsequent interstitial hemorrhage
• Chronic
  
  • extensive parenchymal fibrosis is seen, with reduced number and size of acini with (initially) relative sparing of the islets, and variable dilation of the pancreatic ducts.

Question 7

How can chronic pancreatitis lead to pancreatic insufficiency?

Answer 7

due to irreversible loss of acinar tissue

Question 8

What does fat necrosis looks like grossly?

Answer 8

soft, chalky white areas

Question 9

What are the gross and microscopic findings in type I autoimmune pancreatitis?

Answer 9

• Gross
  
  • may form a mass and mimic pancreatic cancer
• Microscopic
  
  • lymphocytic sclerosing pancreatitis with increased IgG4 producing plasma cells

Question 10

How is autoimmune pancreatitis is treated?

Answer 10

glucocorticoids

Question 11

What is IgG4 related disease?

Answer 11

• Newly recognized fibroinflammatory condition characterized by:
  
  • tumefactive lesions
  • dense lymphoplasmacytic infiltrate rich in IgG4-positive plasma cells
  • storiform fibrosis
  • obliterative phlebitis
  • in some cases, elevated serum IgG4
• Analogous to sarcoidosis

Question 12

What are list some examples of previously named entities that may be a manifestation of IgG4 related disease?

Answer 12

• Mikulicz disease
• Küttner’s tumor
• Riedel’s thyroiditis
• Eosinophilic angiocentric fibrosis
• Multifocal fibrosclerosis
• Lymphoplasmacytic sclerosing pancreatitis/autoimmune pancreatitis
• Fibrosing mediastinitis

Question 13

What are the two most common causes of pancreatic pseudocyst?

Answer 13

acute pancreatitis or trauma

Question 14

What does the microscopic appearance of a pancreatic pseudocyst look like?

Answer 14

Localized collection of pancreatic fluid secretions, with an inflammatory fibrous cyst wall that lacks an epithelial lining

Question 15

What are the key clinical and pathologic features of serous (microcystic) cystadenoma?

Answer 15

• Clinical:
  
  • occurs in older adults
  • patients may present with abdominal pain
  • Surgical resection is usually curative
• Pathological:
  
  • rare
  • benign cystic neoplasm composed of glycogen-rich cuboidal cells surrounding small (1-3 mm) cysts containing clear, thin, straw-colored fluid
  • Accounting for about 25% of pancreatic cystic neoplasms

Question 16

What are the key clinical and pathologic features of a mucinous cystadenoma?

Answer 16

• Clinical:
  
  • typically occur in middle aged women (95%)
  • present as a painless slow-growing mass
• Pathological:
  
  • large multiloculated cysts filled with mucin
  • benign (mucinous cystadenoma) or malignant with tissue invasion (mucinous cystadenocarcinoma)
  • arise in the tail or body of the pancreas, do not communicate with the pancreatic duct

Question 17

What are the key clinical and pathologic features of an intraductal papillary mucinous neoplasm?

Answer 17

• Clinical:
  
  • affect both men and women, usually older adults
• Pathological:
  
  • involve the head of the pancreas more often than the tail
  • communicates with the pancreatic duct system and lacks the “ovarian type” stroma
  • the duct system is dilated
  • precursor to pancreatic adenocarcinoma

Question 18

Out of the following, which ones can become malignant?

• serous (microcystic) cystadenoma
• mucinous cystadenoma
• intraductal papillary mucinous neoplasm

Answer 18

Mucinous Cystadenoma

and

Intraductal Papillary Mucinous Neoplasm (IPMN)

Question 19

Where does pancreatic cancer rank in the list of causes of cancer deaths?

Answer 19

fourth leading cause of cancer deaths

Question 20

What is the most common type of pancreatic carcinoma?

Answer 20

pancreatic ductal carcinoma

Question 21

What are the risk factors for the most common type of pancreatic carcinoma?

Answer 21

• cigarette smoking
• obesity and physical inactivity
• diabetes
• chronic pancreatitis
• family history (5-10% of patients with pancreatic cancer have had a first degree relative with the disease)
• specific inherited predispositions
• hereditary pancreatitis

Question 22

What are the typical clinical presentations of the most common type of pancreatic carcinoma?

Answer 22

• over the age of 60
• pain (abdominal, epigastric, back)
• obstructive jaundice (tumor in the head of the pancreas compresses bile duct)
• weight loss and weakness (advanced disease)
• small number of patients → migratory thrombophlebitis (due to platelet-aggregating factors and procoagulants released by the adenocarcinoma)
• typically remain silent until they invade into adjacent structures

Question 23

Why is pancreatic carcinoma frequently unresectable?

Answer 23

Metastases to peripancreatic lymph nodes and liver are common because pancreatic carcinomas typically remain silent until they invade into adjacent structures.

***tumors are also usually ill-defined

Question 24

How is pancreatic carcinoma diagnosed?

Answer 24

• imaging study that demonstrates a mass lesion
• followed by tissue biopsy
  
  • using endoscopic ultrasound guided (EUS) biopsy technique

Question 25

What is the Whipple procedure that is used in the treatment of pancreatic cancer?

Answer 25

• Pancreaticoduodenectomy
  
  • partial removal of the pancreas, part of the small intestine and the gallbladder

Question 26

What is the difference between the gross appearance and clinical course of pancreatic neuroendocrine tumors versus typical pancreatic adenocarcinoma?

Answer 26

• Pancreatic neuroendocrine:
  
  • Gross: well differentiated, relatively small, and well circumscribed
    
    • found in tail of pancreas
  • Clinical course: present in peripancreatic lymph nodes and liver
    
    • prolonged clnical course
• Pancreatic adenocarcinoma:
  
  • Gross: ill-defined
  • Clinical course: fatal, <30% five-year survival rate

Question 27

What types of hormones (and resulting clinical presentations) can functioning pancreatic neuroendocrine tumors produce?

Answer 27

• Hyperinsulinism → hypoglycemia
• Gastrin → peptic ulcers
• Glucagon
• Somatostatin
• Vasoactive Intestinal Peptide (VIP)
• ACTH → Cushings syndrome

Question 28

What is a “phrygian cap” of the gallbladder?

Answer 28

Folded fundus

(fundus of gallbladder folds over on itself)

Question 29

What are the risk factors for the formation of cholesterol versus pigment gallstones?

Answer 29

• Cholesterol:
  
  • individuals from N. Europe and N. and S. America
  • Increasing age
  • Obesity/metabolic syndrome
  • Female gender
  • multiparity (estrogen exposure)
  • Rapid weight loss
• Pigment:
  
  • individuals from eastern Asia (due to increased incidence of bacterial and parasitic biliary infections)
  • disorders with increased destruction of RBC’s (hemolysis)
  • biliary tract infections (increase in unconjugated bilirubin)

Question 30

What imaging modality is typically used to detect gallstones?

Answer 30

Only 10-15% of gallstones are radiopaque (pigment stones are more likely to be radiopaque than cholesterol stones because of more calcium carbonate and phosphates); use ultrasound to visualize.

Question 31

What are some complications of gallstones, particularly complications of acute cholecystitis?

Answer 31

• gallbladder perforation
• bile peritonitis
• acute cholangitis
• sepsis
• biliary-enteric fistula
• gallstone ileus
  
  • stone enters small bowel by way of the fistula, and can become trapped at the ileocecal valve, leading to obstruction

Question 32

Define choledocholithiasis.

Answer 32

stones in common bile duct

(most common cause of extrahepatic biliary obstruction)

Question 33

What is the most common cause of extrahepatic biliary obstruction?

Answer 33

Choledocholithiasis

Question 34

Are most gallstones symptomatic?

Answer 34

NO

70-80% of patients with gallstones remain asymptomatic.

Question 35

Define chronic cholecystitis.

Answer 35

• Chronic inflammation of the gallbladder
  
  • Virtually always associated with cholelithiasis.
  • Some cases are secondary to repeated bouts of acute cholecystitis, but most are not.
• Supersaturated bile leads to chronic inflammation (lymphocytes dominant) as well as to the formation of gallstones.

Question 36

Define “porcelain gallbladder.”

Answer 36

Dystrophic calcification of the gallbladder wall

Question 37

What does the gross appearance of cholesterolosis and cholesterol polyp of the gallbladder look like?

Answer 37

• Cholesterolosis:
  
  • appears as yellow mucosal flecks
• Cholesterol polyp:
  
  • yellow, small polyps associated with cholesterolosis

Question 38

What is an adenomyoma of the gallbladder? Is this lesion neoplastic?

Answer 38

• Lesion consists of gallbladder diverticulae with focal muscular hypertrophy of the gallbladder muscle wall
  
  • usually located at the fundus
• This lesion is not a true neoplasm, and appears as an intramural thickening of the fundic wall of the gallbladder.

Question 39

What is a risk factor for gallbladder carcinoma?

Answer 39

• Age
  
  • 90% of patients are over the age of 50.
• Typically associated with cholelithiasis (95%).

Question 40

Why is the survival rate for carcinoma of the gallbladder so low?

Answer 40

In most cases the tumor has spread centrifugally directly to the liver or metastasized to regional lymph nodes by the time symptoms appear

(this is a “silent tumor” like pancreatic carcinoma).

The 5 year survival rate is very low (10%).

Question 41

What is the most common type of gallbladder carcinoma?

Answer 41

most are adenocarcinomas (95%)

Question 42

By location, what are the three types of cholangiocarcinomas?

Answer 42

• intrahepatic cholangiocarcinoma
• perihilar cholangiocarcinoma
• distal extrahepatic cholangiocarcinoma

Question 43

Define periampullary carcinoma.

Answer 43

• Tumors of the ampulla of Vater include tumors arising from:
  
  • the duodenal mucosa
  • pancreatic duct
  • bile duct

Question 44

What are some risk factors for extrahepatic cholangiocarcinoma?

Answer 44

• Age
• conditions resulting in chronic cholangitis
  
  • infection with liver flukes (Opisthorchis and Clonorchis),
• PSC
• choledochal cysts

Question 45

What are the clinical presentations and laboratory findings seen in extrahepatic cholangiocarcinoma?

Answer 45

• Clinical presentations
  
  • with painless jaundice secondary to obstruction
    
    • very similar to pancreatic cancer presentation
• Laboratory findings
  
  • increase in alkaline phosphatase, GGT

Question 46

Would you agree that the clinical presentation is similar to that seen in carcinoma of the head of the pancreas?

Answer 46

YES

obstruction symptoms, painless jaundice

Question 47

How would you proceed in evaluating a patient with cholangiocarcinoma?

Answer 47

• demonstration of obstructing lesion
• tissue biopsy or cytology indicating malignancy
• CT scan
• endoscopy with EUS and FNA
• ERCP with cytology brushings and biopsy
• surgical biopsy

Question 48

Why is the prognosis so poor for a cholangiocarcinoma tumor? Why is it better for periampullary carcinoma?

Answer 48

• Periampullary → presents with obstruction right away, so they are often caught sooner