Paraneoplastic hypoglycaemia secondary to IGF-2 secretion from a metastatic gastrointestinal stromal tumour

Abstract

We report the case of a 79-year-old male with previous history of non-Hodgkin's lymphoma in remission, who presented acutely to the Accident and Emergency department with recurrent episodes of hypoglycaemia. At the time of presentation, a random glucose was low at 1.4 mmol/l, which upon correction resolved his symptoms. In hindsight, the patient recalled having had similar episodes periodically over the past 2 months to which he did not give much notice. While hospitalized, he continued having episodes of symptomatic hypoglycaemia, requiring treatment with intravenous dextrose and per os steroids. Once stable, he was discharged on oral prednisolone and dietary advice. A computed tomography scan performed during inpatient stay showed multiple deposits in the abdomen. An ultrasound guided biopsy of one of the liver deposits was performed. Immunohistochemistry supported the diagnosis of a gastrointestinal stromal tumour (GIST) positive for CD34 and CD117. The diagnosis of non-islet cell tumour hypoglycaemia (NICTH) secondary to an IGF2 secreting GIST was confirmed with further biochemical investigations (IGF2=105.9 nmol/l; IGF2:IGF1 ratio 23, Upper Level of Normal (ULN) <10). Targeted cytoreductive treatment with Imatinib mesylate following assessment of the tumour's mutational status was successful in preventing hypoglycaemia over a 21-month follow-up observation period.

Keywords

• Paraneoplastic
• Hypoglycaemia
• Non-islet cell tumour
• GIST
• Imatinib
• IGF-2