Endocrine Abstracts

Background: Fasting hypoglycaemia is a common presenting symptom of insulinoma. However, insulinoma should be considered as a potential cause in those presenting with symptoms of hypoglycaemia after meal (1, 2, 3). Here we report a case who initially presented with postprandial symptoms though there was evidence of fasting hypoglycaemia subsequently.

Case report: A 57-year-old lady initially presented with a 2 years history of palpitation, feeling hot, sweating and dizzy episodes which occurred within 2 h of meals. She also gained some weight. There was no history of nocturnal or fasting hypoglycaemia. Past medical history included CREST syndrome. There was no family history of note. On examination she has a BMI of 34.5.

Thyroid function tests, plasma metanephrines, short synacthen test, urea and electrolytes, renal and liver function tests were normal. Further monitoring of capillary glucose revealed fasting hypoglycaemia.

Subsequently, a supervised 48-h fast test was performed. Patient developed hypoglycaemia within first 12 h. The lowest blood glucose level was 2.2 mmol/l. There were elevated insulin level 49 pmol/l and pro-insulin level 22.2 pmol/l. C-peptide level was 863 pmol/l. Sulphonylurea screen was negative. Hypoglycemia was associated with neuroglycopenic symptoms particularly very aggressive behaviour.

CT scan of the abdomen and endoscopic ultrasound (EUS) have confirmed 1.2 mm solitary insulinoma in the tail of pancreas.

Conclusion: This case has highlighted the importance of awareness of post prandial hypogycemic symptoms as presenting feature of insulinoma.

References: 1. Placzkowski KA, Vella A, Thompson GB, Grant CS, Reading CC, Charboneau JW, et al. Secular trends in the presentation and management of functioning insulinoma at the Mayo Clinic, 1987–2007. J Clin Endocrinol Metab. 2009 94 (4) 1069–73.

2. Madathil A, Weaver J. Insulinoma presenting as postprandial hypoglycaemia. BMJ Case Rep. 2011 2011.

3. Connor H, Scarpello JH. An insulinoma presenting with reactive hypoglycaemia. Postgrad Med J. 1979 55 (648) 735–8.