Tumour‐induced hypoglycaemia due to ‘big’ IGF–II

. A 57‐year‐old woman with a slowly growing intraabdominal leiomyosarcoma developed life‐threatening hypoglycaemia. Plasma C‐peptide levels were low (0.08 nmol L ‐1 and < 0.05 nmol L ‐1 , reference interval 0.18–0.63 nmol L ‐1 ). Total IGF–II was normal (760 ng mL ‐1 ) whilst ‘big’ IGF–II was markedly elevated (440 ng mL ‐1 ). After surgical tumour reduction, ‘big’ IGF–II levels in plasma normalized (117 ng mL ‐1 ) and the patient experienced no new episodes of hypoglycaemia. Life‐threatening hypoglycaemia due to tumour production of IGF–II can be ameliorated by reduction of the tumour burden and should be kept in mind even in incurable patients.