Pancreatic ductal adenocarcinoma
- Lesion
Pancreatic cancer is hard, invasive and found late; in the head it blocks the bile duct and causes painless jaundice.
What it is
Pancreatic ductal adenocarcinoma is one of the deadliest cancers: most patients are diagnosed with locally advanced or metastatic disease. Smoking is the strongest environmental risk factor, followed by chronic pancreatitis, obesity and long-standing diabetes; inherited syndromes explain a minority. Most tumours arise in the head of the pancreas. The tumour is very infiltrative, with dense desmoplastic stroma, and spreads along nerves and vessels early.
Structure
- Gross: hard, stellate, grey-white mass with poorly defined edges; obstructs the common bile and pancreatic ducts in the head.
- Micro: moderately to poorly differentiated glands of mucin-producing cells in abundant collagen; perineural invasion; variants include adenosquamous, colloid (with IPMN), medullary and undifferentiated with osteoclast-like giant cells.
Step by step
- Precursor lesions accumulate KRAS, CDKN2A, TP53 and SMAD4 changes.
- Invasive cells recruit and activate stellate cells that build a dense desmoplastic stroma.
- The stroma is hypovascular and immunosuppressive, which limits drug delivery and immune attack.
- Cancer cells track along nerves (pain) and vessels.
- Head tumours block bile flow (jaundice); spread to liver, peritoneum and lungs follows.
- Tumour mucins and tissue factor activate coagulation: migratory thrombophlebitis.
Markers
- CA 19-9 (serum)
- Keratin 7
- Loss of SMAD4 (DPC4)
- CEA
Clinical notes
- Painless jaundice, weight loss, epigastric pain radiating to the back, new-onset diabetes in an older adult.
- Only a minority are resectable at diagnosis; pancreaticoduodenectomy (Whipple) for head tumours.
Test yourself
Think of the answer, then tap the question to see it.
What is the strongest environmental risk factor for pancreatic adenocarcinoma?
Cigarette smoking.
What is the Trousseau sign of malignancy?
Migratory superficial thrombophlebitis caused by tumour-derived procoagulants, classically with pancreatic cancer.
Why do carcinomas of the pancreatic head often present earlier than tail tumours?
They compress the common bile duct and cause obstructive jaundice; body and tail tumours grow silently.
What is the role of CA 19-9 in pancreatic cancer?
Monitoring response and recurrence; it is not specific or sensitive enough for screening.
Connections
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Pancreatic Cancer (StatPearls (NCBI Bookshelf), 2024); Pancreatic Cancer and Pancreatic Neuroendocrine Tumor - NCI (National Cancer Institute, 2026).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.