18. Spontaneous Hypoglycaemia

Spontaneous hypoglycaemia has a very wide differential diagnosis that depends in a large part on clinical context. A hypoglycaemic disorder should only be confirmed if all three parts of Whipple’s Triad are met. In the context of a patient presenting to an out-patient department with suspected hypoglycaemia, confirmation will usually require prolonged fasting. If a hypoglycaemic disorder is confirmed, measurement of serum insulin and c-peptide concentrations at the time of biochemical hypoglycaemia will help to refine the diagnostic possibilities. Non-islet cell tumour hypoglycaemia (NICTH) is a rare cause of spontaneous hypoglycaemia, which occurs usually in the context of malignant sarcomas with significant tumour bulk. Hypoglycaemia is associated with high serum levels of an abnormal IGF-2 protein. Treatment of NICTH is difficult, especially if the tumour cannot be successfully resected or debulked, and usually revolves around systemic glucocorticoid therapy in high dose.