Nesidioblastosis and Persistent Hyperinsulinemic Hypoglycemia: Are They Related?

Aneonate delivered to a nondiabetic mother at 30 weeks’ gestation experienced symptoms of severe hypoglycemia within hours of birth. The neonate required a continuous high-glucose infusion rate to maintain euglycemia. Based on the finding of an inappropriately elevated plasma insulin level concurrent with low glucose levels, the diagnosis of persistent hyperinsulinemic hypoglycemia of infancy (PHHI) was rendered. Medical treatment was ineffective in preventing hypoglycemia, necessitating surgical intervention. A 90% pancreatectomy was performed when the neonate was 16 days old. After surgery, the neonate recovered fully but later had insulin-dependent diabetes develop. Results of genetic studies were unremarkable. Histologic, immunohistochemical, and electron microscopic examinations of the pancreas demonstrated findings consistent with the diagnosis of the diffuse type of nesidioblastosis. The literature on nesidioblastosis is reviewed, and current theories regarding its origin, significance, and relationship to PHHI are discussed.