Hyperinsulinaemic hypoglycaemia due to chlorpropamide-induced nesidioblastosis.

A 25 year old woman suffering from recurrent attacks of hypoglycaemia underwent a laparotomy for suspected insulinoma. No tumour was found, but histology showed islet cell hyperplasia and nesidioblastosis. Although these changes have been reported as a cause of hypoglycaemia in infants, they are only rarely the cause of hypoglycaemia in adults; in the present case they were found to be the result of covert sulphonylurea administration. The fact that sulphonylureas can cause nesidioblastosis is not well recognised by either physicians or pathologists and it should be considered before "cryptogenic nesidioblastosis" is deemed the cause of hypoglycaemia in adults.