Recurrent insulin-independent hypoglycemia

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N. Holle, E. van der Spek, H. de Boer

Woensdag 20 april 2016

15:30 - 15:40u in Auditorium 2

Categorieën: Parallelsessie

Parallel sessie: Parallelsessie 2: Case reports/research

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Introduction: Hypoglycemia not associated with diabetes mellitus is rare, particular if it is not related to endogenous hyperinsulinism or adrenal insufficiency. We present an elderly patient with severe hypoglycemia without significant medical history.

Case description: A 72-year old patient was referred to our emergency care unit because of reduced consciousness and severe hypothermia (29 °C). Physical examination was normal, but a rapid blood test revealed a glucose level of 1,3 mmol/L. Consciousness and normothermia was regained after receiving glucose intravenously and warm blankets. Insulin and C-peptide levels measured at the time of hypoglycemia were suppressed, whereas IGF-1 (279 ng/ml; 52-165) and IGF-2 (706 ng/ml; 280-610) were both elevated with normal IGFBP3 levels. Additional PET/CT scanning revealed extensive lymphadenopathy due to a follicular non-Hodgkin's lymphoma. A diagnosis of an IGF producing follicular NHL was made and our patient was treated with eight times R-COP chemotherapy. Thereafter she remained free of hypoglycemias for a period of five years. Recently, our patient presented again with hypoglycemia (2,2 mmol/L). Additional imaging showed relapsed NHL with an increase in IGF-1 (32,9 nmol/L; 6.8-28.5). Other laboratory results such as IGF-2, C-peptide, pro-insulin and insulin were normal. After second line treatment, levels of IGF-1 returned to normal and hypoglycemia has not been seen since.

Conclusion: We describe a patient with severe hypoglycemia due to an IGF producing follicular non Hodgkin lymphoma. Mechanisms other than excess of insulin are uncommon, but should be kept in mind. Hypoglycemia can be the first paraneoplastic symptom with potentially serious consequences.