Editing Pancreatic neuroendocrine tumours (section)

==== '''Insulinoma''' (most common) ====

*** Summary
**** Most common
**** Typically small and benign - average size 1-1.5cm
**** >99% found in pancreas - uniformly distributed throughout pancreas
**** <10% are malignant
**** Majority sporadic
*** Presentation
**** Age 40-45
**** Symptoms caused by hypoglycaemia - headaches, confusion, visual disturbances, or catecholamines causing palpitations, sweating, tremors
**** '''Whipple's triad''' - symptoms of hypoglycaemia, BSL < 4, relief of symptoms with administration of glucose
*** Diagnosis
**** Elevated insulin to glucose ratio during fasting, with associated elevated levels of C-peptide
**** Gold standard is a 48 hour fasting test, with levels every 6 hours
**** Can be difficult to localise previously, but now fairly straightforward with EUS
***** Initial CT/MRI
***** Can try somatostatin receptor scan - but again often misses it
***** EUS positive in 70-95% of cases
**** Distributed equally throughout the pancreas, and can occur in duodenum, splenic hilum, or gastrocolic ligament

* Treatment
** Medical - small, frequent meals and control of hypoglycaemia
** Enucleation best surgery - cure 85-95%
*** Can be done safely if tumour is 2-3mm from PD
** Pancreatic resection less common, generally unnecessary
** Operative exploration - can find it via palpation and USS 92% of the time
*** Blind distal resection is not recommended if unable to find it
**