🧬 Congenital anomalies
- agenesis Complete absence of pancreas → incompatible with life.
- pancreas divisum Most common ductal variant: dorsal and ventral ducts fail to fuse.
- Usually asymptomatic, but may predispose to recurrent pancreatitis.
- annular pancreas Pancreatic tissue encircles the duodenum.
- Presents as duodenal obstruction (neonatal or adult).
- Associated with other congenital anomalies (e.g., Down syndrome).
- ectopic tissue Aberrant pancreatic rests in stomach, duodenum, or jejunum.
- Can hemorrhage, become inflamed, or rarely give rise to neuroendocrine tumors.
- Annular pancreas can be suspected on plain X‑ray as “double‑bubble” sign in neonates.
🔥 Acute pancreatitis
- definition Acute inflammation of the exocrine pancreas with enzymatic autodigestion.
- etiologies Diverse triggers:
- Gallstones (most common)
- Alcohol (second most common)
- Hypercalcemia, hypertriglyceridemia
- Drugs (e.g., sulfonamides, valproate)
- Shock, ischemia, trauma, infections (mumps, Coxsackie)
- Scorpion stings (rare)
- pathogenesis Acinar injury → premature activation of trypsinogen → pancreatic enzyme cascade.
Acinar injury→ Trypsin activation→ Autodigestion→ Inflammation + necrosis
- clinical Stabbing epigastric pain radiating to the back; nausea, vomiting.
- Severe cases: shock, ARDS, DIC, renal failure.
- labs Elevated serum amylase and lipase (lipase more specific).
- complications
- Pancreatic pseudocyst (fluid collection without epithelial lining).
- Pancreatic calcifications, hypocalcemia (fat saponification).
- ARDS, DIC, multi‑organ failure.
- pathology Gross: focal hemorrhage, liquefaction, chalky white‑yellow fat necrosis.
- Micro: liquefactive necrosis, acute inflammation, enzymatic fat necrosis.
- Vessel necrosis → hemorrhage.
- Mortality in severe acute pancreatitis: ~30% — early recognition is critical.
⏳ Chronic & autoimmune pancreatitis
- chronic pancreatitis Irreversible fibrosis, atrophy, and functional loss.
- Most common in middle‑aged male alcoholics.
- Manifestations: abdominal pain, malabsorption, pancreatic calcifications, pseudocyst, secondary diabetes (late).
- pathology Gross: firm, white, fibrotic pancreas. Micro: extensive fibrosis, parenchymal atrophy, chronic inflammation.
- autoimmune Associated with IgG4‑related fibrosing disorders.
- Responds to steroid therapy.
- May present with obstructive jaundice (mimics pancreatic cancer).
- Secondary diabetes in chronic pancreatitis is due to islet cell destruction — not insulin resistance.
🧫 Neuroendocrine tumors (islet cell)
- Less common than exocrine tumors. Most are low‑grade malignancies.
- Some are non‑functional (no hormone excess).
- Gross/histology does not distinguish subtypes.
| Tumor | Cell / hormone | Key features |
|---|---|---|
| Insulinoma | β‑cell / insulin | Hypoglycemia, sweating, confusion; surgical cure. |
| Gastrinoma | G‑cell / gastrin | Zollinger‑Ellison (thick gastric folds, hyperacidity, ulcers); may be extrapancreatic; associated with MEN1. |
| Glucagonoma | α‑cell / glucagon | Hyperglycemia, anemia, necrolytic migratory erythema. |
| Somatostatinoma | δ‑cell / somatostatin | Diabetes (inhibits insulin), hypochlorhydria, gallstones, steatorrhea; poor prognosis. |
| VIPoma | VIP | WDHA: Watery diarrhea, Hypokalemia, Achlorhydria. |
🧬 Adenocarcinoma
- epidemiology 3rd most common cause of cancer death in the US. Age 60–80.
- risk factors Smoking, chronic pancreatitis, diabetes, family history.
- presentation Vague until late. Later: abdominal pain, migratory thrombophlebitis (Trousseau), obstructive jaundice (head tumors).
- location Head (60%), body (15%), tail (5%).
- pathology Ductal adenocarcinoma with desmoplasia and perineural invasion (hallmark).
- Markers: CA19‑9, CEA (not for screening).
- treatment Surgical excision (Whipple procedure) for localized disease.
- prognosis Very poor; 5‑year survival ~5%.
- Perineural invasion is a classic feature and contributes to pain and high recurrence.
🫧 Cystic neoplasms
- serous ~25% of pancreatic cystic neoplasms. Mostly benign (cystadenoma).
- Associated with VHL mutation.
- mucinous cystic neoplasm Common in women; can harbor dysplasia or carcinoma.
- Distal pancreatectomy is curative in most.
- intraductal papillary mucinous neoplasm (IPMN) More common in men, arises in the head.
- GNAS mutations frequent; risk of invasive carcinoma.
- IPMN is a premalignant lesion — surveillance or resection based on risk features.