Nesidioblastosis is a controversial medical term for
hyperinsulinemic hypoglycemia attributed to excessive function of
pancreatic beta cells with an abnormal
microscopic appearance. The term was coined in the first half of the 20th century. The abnormal
histologic aspects of the tissue included the presence of islet cell enlargement, islet cell
dysplasia, beta cells budding from ductal epithelium, and islets in apposition to ducts.