Changing concepts of islet cell dysplasia in neonatal and infantile hyperinsulinism

Neonatal and infantile hypoglycemia due to insulin excess has been associated with a spectrum of anatomic changes, i.e., nesidioblastosis, endocrine cell dysplasia, islet cell hyperplasia, and adenomatosis. The mechanism of hyperinsulinemia in these patients has been attributed to: (a) an increase in islet cell mass, (b) abnormal islet cell architecture with alternation in paracrine function, (c) imbalance of alpha, beta, and delta cell secretion, and (d) a regulatory defect of insulin secretion. Morphometric, immunocytochemical, and electron microscopy studies have not substantiated an increase in endocrine cell mass in many patients. Nesidioblastosis is believed to be a normal phase of fetal development of the pancreas rather than a pathologic entity. A regulatory defect in insulin storage and release is the best explanation of hyperinsulinism in these patients . We report experience with 165 neonates and infants including 6 of our own collected during the last decade. Subtotal pancreatectomy (79–90%) was carried out as the initial operative procedure in 76% of patients. Twenty‐eight percent required a second operation of near‐total to total pancreatectomy. Eleven percent required a third procedure. A near‐total pancreatectomy (95–98%) was performed as the initial operation in 24% of the patients. Five percent of these patients required a second operation . There is a clear advantage of performing an extensive pancreatectomy (95–98%) at the initial operative procedure. In the 40 patients so treated, the incidence of mental retardation was 12.5% and seizures, 2.5%. Ten percent required diazoxide for further management, and 7.5% required insulin on a long‐term basis. Mortality was 2.5%. In our report, covering experience from 1934 to 1971, the mortality was 8.3% and mental retardation, 52% .