GCG and pancreatic insulinoma: While the detection of insulinoma (single or rarely multifocal forms) in some cases still remains a clinical challenge for four years [Lys40(Ahx-HYNIC-99mTc/EDDA)NH2]-exendin-4 (technetium-99m labelled long acting glucagon-like peptide analogue; 99mTc-GLP) scintigraphy has been developed in our centre as a potential and crucial imaging technique in such cases.