Based on observations of five of own patients the author analyzes the causes of spontaneous hypoglycaemia in malignant tumours and assumes three mechanisms of development: 1. Metastatic affection of the liver reduces the reserves of homeostatically usable glycogen and can reduce also the amount of utilized insulin and glucagon, and this weakens the effectivity of contraregulating hormones. 2. In case of large mesenchymal tumours it is assumed that the cause of hypoglycaemia is the neoplastic formation of IGF II. For these hypoglycaemic states a low concentration of C-peptide, IRI (immunoreactive insulin), absence of response of growth hormone to hypoglycaemia, high IGF II in the tumour and plasma and high mRNA for IGF II in the tumour is typical. 3. In hypoglycaemic states with massive metastases in the liver, high IRI and C-peptide it is assumed the cause of hypoglycaemia is a metastatizing insular tumour or a nes.dioblastoma. In those instances concurrent peptic ulcers (gastrin production) are frequent.

Keywords: Adult; Aged; Humans; Hypoglycemia /etiology/; Male; Middle Aged; Neurocognitive Disorders /etiology/; Paraneoplastic Syndromes /metabolism/