Neoplasma Vol.62, No.6, p.841-845, 2015

Tumor hypoglycemia is rare but life-threatening medical condition which may be associated with insulinoma and non-islet cell tumors (mainly of mesenchymal origin). The pathogenesis is connected with abnormal processing of insulin-like growth factor-2 (IGF-2) precursor and production of pathognomic „big“ IGF-2 – incompletely processed posttranslational precursor of IGF-2, which is responsible for hypoglycemia. Other typical laboratory features include low level of fasting glucose and C-peptide, low IGF-1 and increased IGF-2 : IGF-1 ratio. Although paraneoplastic hypoglycemia is often present in patients with already diagnosed malignancy, it is necessary to consider this possibility in patients having unclear and inexplicable hypoglycemia. The adequate treatment can significantly reduce the symptoms and improve the quality of life.