The Role of Glucagon-Like Peptide 1 Receptor PET/CT With Ga-68-NODAGA-exendin in Localising an Insulinoma: Lessons From a Clinical Case

We present a clinical case highlighting the diagnostic challenges in a patient with an insulinoma. A 57-year-old lady initially presented with sweating on waking. Investigation documented a fasting blood glucose of 2 mmol/L (3.9-5.4) and the presence of anti-endomysial antibodies. On the basis of a diagnosis of Coeliac disease, the patient was commenced on a gluten free diet with apparent resolution of symptoms for 9 years. Subsequently, she re-presented with recurrent episodes of confusion which resolved with a ‘sugary’ drink. Consequently, she underwent a prolonged supervised fast: glucose 1.9 mmol/L (neuroglycopaenic symptoms), insulin 76 pmol/L (90% of insulinomas and this case underlines the utility of GLP-1R PET/CT in insulinoma localisation.