A well-circumscribed, avidly arterial-enhancing pancreatic mass without duct dilatation — then size, the duct, vessels, liver metastases (also arterially enhancing) and the functioning syndrome that sent the patient.
Orient first
- Most are non-functioning and found incidentally; insulinomas are small (often < 2 cm) and are sought because of hypoglycaemia.
- Unlike adenocarcinoma, they enhance avidly in the arterial phase, rarely obstruct the duct, and can be cystic or calcified.
- Liver metastases are hypervascular — the late arterial phase must be read, not only the portal venous.
Acquire the study
- Late arterial (pancreatic) phase at ~40 s and portal venous phase, 1 mm slices with curved reformats along the duct.
The manoeuvre
- Late arterial phase: hyperenhancing, well-defined mass; measure in mm.
- Main pancreatic duct calibre upstream — dilatation raises grade or suggests another tumour type.
- SMV/portal vein: tumour thrombus (enhancing) rather than bland thrombus.
- Liver: hypervascular metastases on the arterial phase that may be invisible on the portal venous phase.
What confirms it
- A hyperenhancing pancreatic mass without duct obstruction, with the functioning syndrome or somatostatin-receptor avidity; histology grades it.
What licenses you to exclude it
- A negative pancreatic-protocol CT does not exclude a small insulinoma — endoscopic ultrasound is the next step.
The classic misread
- Calling a small insulinoma the normal pancreatic head because only the portal phase was acquired.