Problems of differential diagnosis of paraneoplastic hypoglycaemia

: Paraneoplastic hypoglycaemia is relatively rare. The most common cause is insulinoma, tumour from pancreatic beta cells with insulin production. Fasting glycaemia together with hyperinsulinaemia during 24 hours of fasting is characteristically present. Endoscopic ultrasonography is the most sensitive method for localization of insulinoma, scintigraphy with labelled GLP-1 analogs and modified positron emission tomography are new perspective methods. Non-beta-cells tumours are mesenchymal or epithelial tumours with huge size, slow growth and increased production of insulin like growth factor IGF-2 (IGF-2oma). Fasting hypoglycaemia in this case is associated with increased levels of total and free IGF-2 as well as big IGF-2 form. Due to suppression effect there are decreased levels of insulin, growth hormone and IGF-1 and ratio IGF-2/IGF-1 is typically increased. In opposite to insulinoma diagnosis of non-beta-cells tumour mostly precedes the occurrence of hypoglycaemia.Key words: insulin like growth factor-2 (IGF-2) - insulinoma - non-beta-cells tumours - paraneoplastic hypoglycaemia insulin.