The three CT images were obtained pre-contrast, arterial phase and portal phase. The arterial phase shows a subtle enhancing mass in the tail of the pancreas measuring about 2 cm in diameter. The MRI T2-weighted fat suppressed images show the mass in the tail of the pancreas to be of increased signal compared to the remainder of the pancreas. An incidental accessory spleen is noted in the splenic hilum cephalad to the tail of the pancreas.
Calcium arterial stimulation with venous sampling was performed to confirm the localization of the insulinoma in the tail of the pancreas. A calcium solution was injected at different times into the splenic, hepatic and superior mesenteric arteries with sampling from the right hepatic vein for insulin levels several times over two minutes each.