Paraneoplastic hypoglycemia

Mouna Elleuch; Yassmine Abdelkafi; Khouloud Boujelben; Faten Hadjkacem; Rihab Khochtali; Souhir Maalej; Nadia Charfi; Fatma Mnif; Mouna Mnif; Salah Dhoha Ben; Mohamed Abid; Nabila Rekik

doi:10.1530/endoabs.99.EP83

Introduction: Non-Islet Cell Tumor Hypoglycemia (NICTH) is a rare but serious condition. We report a case of NICTH in a patient with a gastrointestinal stromal tumor.

Observation: The patient was a 56-year-old with a history of metastatic gastrointestinal stromal tumor (GIST), diagnosed and operated on in 2016. He received tyrosine kinase inhibitors: Imatinib for 5 years, followed by sunitinib with two courses, and was later declared in palliative care due to tumor progression. He was admitted to the endocrinology department for exploration of recent severe hypoglycemic episodes occurring unexpectedly at any time of the day, with a capillary blood glucose level of 0.15 g/l at admission. Iatrogenic causes were ruled out through questioning, and general pathologies were eliminated based on normal test results. Hormone counter-regulation deficiencies were also excluded. Endogenous hyperinsulinism was refuted with insulin levels at 1 mIU/l, a collapsed C-peptide level at 0.04 ug/l, and a concurrent venous blood glucose level of 2 mmol/l. IGFII level was normal at 444 ng/ml, while IGFI level was suppressed at 30.5 ng/ml. NICTH was confirmed with an IGFII/IGFI ratio>10. The patient was treated with corticosteroids at a dose of 80 mg/day in four divided doses (20 mg×4/day). The course of the disease showed a decrease in the frequency and severity of hypoglycemic episodes. However, the patient succumbed to the progression of his illness one month later.

Discussion: NICTH is attributed to the secretion of an abnormal IGFII molecule, mainly by malignant tumors such as mesenchymal tumors. This molecule, called BIG IGFII immature, has a threefold stronger effect than mature IGFII. It binds to the insulin receptor, leading to its hypoglycemic effect. Diagnosis is established with an IGFII/IGFI ratio greater than 10. Treatment involves tumor excision, dietary measures to increase caloric intake and the number of snacks, along with corticosteroid therapy at the minimum effective dose. Combining with rhGH (recombinant human growth hormone) may assist in minimizing the doses and side effects of each treatment.

Endocrine Abstracts

EP83