Seen in gastrinoma triangle: junction of cystic and common hepatic duct superiorly, second and third parts of duodenum inferiorly, pancreatic neck medially
Associated with multiple endocrine neoplasia MEN-1
Early enhancement quite often, well seen also in portal phase imaging
Functional imaging useful. PET-CT using somatostatin receptor tracers: Ga 68 DOTATOC / DOTANOC / DOTATATE
Invasive techniques like selective arterial calcium stimulation followed by venous sampling is also useful
Non functioning tumors show calcification and avid contrast enhancement.