RESUMO
Hyperinsulinemic hypoglycemia is a relatively rare disease in childhood period except neonate, but hypoglycemia due to delicate imbalance between glucose production & consumption is evoked easily and left permanent damage to brain at these period. The definition is that serum insulin level is above 10microU/ml when blood sugar level is below the 40mg/dl and so I/G ratio is higher than 0.4. The clinical manifestations are irrtability, frequent feeding and seizures etc. and there is no specific pancreatic pathology in most cases. We experienced 2 cases of hyperinsulinemic hypoglycemia with pancreatic hyperplasia and pancreatic adenoma each other. The diagnosis was made on clinical manifestations, laboratory results, radiologic and pathologic findings. We reported these cases with brief review of literature.