Tumors of the exocrine and endocrine pancreas

1. Tumors of the Exocrine Pancreas

A) Serous cystadenoma

• Glycogen-rich cuboidal cells surrounding small cysts with clear, straw-colored fluid.
• 7th decade, non-specific abdominal pain.
• Almost always benign; surgical resection curative.

B) Mucinous cystic neoplasm

• Almost always in women.
• Body / tail of pancreas; painless, slow-growing.
• Cysts lined by columnar mucinous epithelium, filled with thick mucin.
• 3 forms (spectrum):
  • Benign = mucinous cystadenoma (no atypia)
  • Borderline = mucinous cystic tumor with moderate dysplasia
  • Malignant = mucinous cystadenocarcinoma (invasive)

C) Intraductal papillary-mucinous neoplasm (IPMN)

• 3 forms: IPMA → IPMA with dysplasia → intraductal papillary-mucinous carcinoma.
• Most often in men; head of pancreas.

D) Solid pseudopapillary tumor

• Uncommon; women 20–40 yr.
• Large, encapsulated; cystic + solid + hemorrhagic mixture.
• Low malignant potential; metastases rare; good prognosis after resection.

Spectrum summary

Benign	Borderline	Malignant
Serous cystadenoma	—	—
Mucinous cystadenoma	Mucinous cystic tumor	Mucinous cystadenocarcinoma
IPMA	IPMA w/ dysplasia	Intraductal papillary-mucinous carcinoma
Solid pseudopapillary tumor	—	Solid pseudopapillary carcinoma
—	—	Ductal adenocarcinoma, acinar cell carcinoma, pancreatoblastoma

2. Pancreatic Carcinoma (Ductal Adenocarcinoma)

• One of the most lethal cancers (5-yr survival < 5 %).
• Arises from acquired/inherited mutations in cancer genes (KRAS, p16, p53, SMAD4).
• Distribution: 70 % head, 15 % body, 15 % tail.
• Head tumors → CBD obstruction → distended biliary system + jaundice.
• Majority = ductal adenocarcinoma.
• Distant metastases: lung, bone, liver.

Complications / signs

• Liver + lung metastases.
• Courvoisier’s sign: painless enlarged gallbladder + jaundice → implies pancreatic / biliary malignancy (not stone).
  • Light (acholic) stools, dark urine.
• Trousseau sign (migratory thrombophlebitis): paraneoplastic, due to tumor-derived procoagulants / platelet-aggregating factors.

3. Tumors of the Endocrine Pancreas

General features: benign or malignant; functional (hormone-secreting) or non-functional; solitary or part of MEN-1.

Benign (usually)	Malignant (usually)
Insulinoma	Glucagonoma
PP-cell tumor	Gastrinoma
—	Somatostatinoma, VIPoma

A) Insulinoma (β-cell tumor)

• Most common pancreatic endocrine neoplasm.
• Whipple triad:
  1. Hypoglycemia — blood glucose < 50 mg/dL
  2. CNS symptoms — confusion, stupor, unconsciousness
  3. Relief with glucose; precipitated by fasting/exercise
• Lab: ↑ insulin, ↑ C-peptide, ↑ insulin/glucagon ratio.

B) Gastrinoma

• Hypersecretion of gastrin; arises in duodenum or pancreas.
• Zollinger-Ellison syndrome — extreme gastric acid → multiple / refractory peptic ulcers (often in unusual locations: jejunum).
• Associated with MEN-1.

C) Glucagonoma

• Extremely high glucagon levels.
• Mild DM.
• Necrolytic migratory erythema (characteristic skin rash).
• Anemia.

D) Other functional islet cell tumors

• Somatostatinoma — DM, cholelithiasis, steatorrhea, achlorhydria.
• VIPoma — WDHA syndrome: Watery Diarrhea, Hypokalemia, Achlorhydria.

💡 High-yield: Exocrine: serous cystadenoma (benign), mucinous cystic neoplasm (♀, body/tail, spectrum), IPMN (♂, head), solid pseudopapillary (young ♀). Pancreatic ductal adenocarcinoma = lethal; 70 % in head → obstructive jaundice + Courvoisier sign (painless enlarged gallbladder); paraneoplastic Trousseau sign. Endocrine: Insulinoma = #1, Whipple triad. Gastrinoma = Zollinger-Ellison (peptic ulcers, MEN-1). Glucagonoma = necrolytic migratory erythema + DM + anemia. VIPoma = WDHA.