Pancreatic Tumors

Question 1

Serous Cystadenoma

Answer 1

• Benign; glycogen-rich low cuboidal cells filled w/ serous fluid (clear, straw-colored)
• Thin layer of epithelium; epithelial cells have clear cytoplasm of glycogen
• Usually in women
• Usually slow growing, painless (or ab pain), found incidentally
• Surgical resection
• Genetics = VHL (von Hippel Lindau Disease)

Question 2

Mucinous Cystic Neoplasm (MCN)

Answer 2

• Made of thick mucin; lined by columnar epithelium and DENSE ovarian type STROMA (express progesterone and estrogen receptors)
• Usually in women; in body or tail; not in contact w/ main ducts
• Also painless, slow-growing and found incidentally but can progress to invasive adenocarcinoma
• Often have daughter cysts budding off main cyst
• Genetics = KRAS, RNF43

Question 3

Intraductal Papillary Mucinous Neoplasma (IPMN)

Answer 3

• Also filled w/ mucin and also can progress to adenocarcinoma (esp if in main duct v branch ducts)
• BUT more common in men and in head of pancreas
• Distinguish by NO DENSE STROMA and arise in main pancreatic ducts
• Present w/ evidence of duct obstruction
• Genetics = KRAS, RNF4, GNAS

Question 4

Solid Pseudopapillary Neoplasm

Answer 4

• Mainly in young women
• Genetics = Beta-catennin mutation
• Large, well-circumscribed mass w/ both solid and cystic zones
  
  • Cystic zones filled w/ hemorrhagic debris
  • Solid zones have sheets of cells or papillary projection
• PAS positive hyaline globules
• Can cause ab discomfort b/c so large
• Surgical resection

Question 5

Pancreatic Neuroendocrine Tumors (PanNETS)

Answer 5

• RARE from Islets
• Can be benign or malignant; functional (pancreatic hormones) or non-functional; single or multiple; anywhere in pancreas
• If functional… clinical syndromes include
  
  • Hyperinsulinism
  • Hypergastrinemia (Zollinger-Ellison)
  • Mult endocrine neoplasia
• Pathology
  
  • Solid, well-circumscribed
  • Uniform cells w/ round nuclei arranged in cords, acini or sheets; nested
  • Scattered salt and pepper chromatin
  • Insulinomas = amyloid
  • Somatostatinomas = psammoma bodies

Question 6

2 Solid Tumors of Acinar Parenchyma

Answer 6

1- acinar cell carcinoma (rare; can stain w/ trypsin)

2- pancreaticoblastoma (2/3 kids; squamoid nests)

** Both large, mimic normal acinar parenchyma

Question 7

Ductal Adenocarcinoma Risk Factors and Genetic Disorders

Answer 7

• Risks - age and smoking (2x), chronic pancreatitis, DM, family hx, obesity, genetic syndromes
• Hereditary nonpolyposis colorectal cancer - DNA mismatch repair genes
• Hereditary breast and ovarian cancer - BRCA2
• Hereditary pancreatitis - PRSS1
• Peutz-Jeghers - STK11/LKB1

Question 8

3 Precursors to Ductal Adenocarcinoma

Answer 8

• Pancreatic intraepithelial neoplasm (PanINs) - most common
• IMPN
• MCN

Question 9

How does PanIN progress to ductal adenocarcinoma?

Answer 9

• KRAS –> CDKN2A –> tp53 and SMAD4

- Low-grade dysplasia to high-grade dysplasia

Question 10

Pathology of Ductal Adenocarcinoma

Answer 10

• 60% in head
  
  • Hard, stellate, gray/white, poorly defined mass
  • Poorly differentiated adeno of ductal epithelium
  • Aggressive and deeply infiltrative
  • Dense stromal fibrosis
  • Often perineural invasion and lymphatic invasion
  • Irregular mets to liver, lung, bones

Question 11

Clinical Presentation, Prognosis and Tx in Ductal Adenocarcinoma

Answer 11

• Usually silent for long time then present w/ pain once expands a lot
• If in head may block common bile duct –> obstructive jaundice
• Wt loss, anorexia, malaise late in disease
• Migratory thrombophlebitis
• HIGH mortality; 4th leading cause of cancer death; less than 5% 5 yr survival
• Tx - resection (Whipple if in head and distal pancreatectomy if in body or tail); gemcitabine and 5-FU; radiation; palliative