Disorders of the endocrine pancreas.

Hyperinsulinemic hypoglycemia in the neonate or in early infancy may be caused by an islet cell adenoma or a diffuse organic lesion of the endocrine pancreas such as nesidioblastosis. The 2 disorders cannot be distinguished by biochemical means but only by immunohistochemical analysis after subtotal pancreatectomy. An aggressive therapeutic approach is mandatory to avoid permanent neurological damage. In nesidioblastosis, 20% of patients are healed by subtotal pancreatectomy and the remainder may be controlled by postoperative treatment with diazoxide and hydrochlorothiazide. Some patients may need total pancreatectomy which leads to permanent insulin-dependent diabetes in most of them. When hyperinsulinemic hypoglycemia first manifests after 1 year of age, it is always caused by an islet cell adenoma, which is cured by enucleation.