• Nesidioblastosis (NB) is a disease characterized by hyperfunctioning pancreatic β cells, usually associated with hypoglycemia in the presence of high endogenous insulin levels. It is necessary to exclude insulinoma or exogenous insulin of sulfonylurea administration when making the diagnosis.
  • Most commonly described in neonates and children, but recent studies have shown an increased number of cases in adults
    • Focal NB: confined to one discrete area of the pancreas
    • Diffuse NB: All or most islet cells are affected.
  • Most common cause of persistent hyperinsulinemic hypoglycemia in neonates
  • Synonym(s): noninsulinoma pancreatogenous hypoglycemia (NIPHS); persistent hyperinsulinemic hypoglycemia of infancy (PHHI); congenital hyperinsulinism; islet cell hyperplasia


Few data available on the incidence of disease


  • Infants/children
    • Sporadic: 1/30,000 to 1/50,000 live births
    • Familial: 1/2,500 births have been seen.
  • Adults: 0.5–15% of organic hyperinsulinemias
    • Annual incidence is 0.09/100,000.
    • Peaks in 5th decade of life

Etiology and Pathophysiology

NB involves hyperplastic pancreatic β cells that hyperfunction and cause excessive insulin secretion. KATP channel activity results with a constant insulin release:

  • Focal NB: accounts for up to 40% of cases and consists of a discrete area of the pancreas with adenomatous hyperplasia of the islet cells
  • Diffuse NB: Most or all β cells in the pancreas show hyperplasia.
  • Most cases have a genetic predisposition; in adults, may involve dysregulation
  • Increase in expression of IGF-2, IGF-1 receptor-α, and TGF-β in islet cells from NB patients compared with controls
  • Associated with gastric bypass surgery; has been associated with other upper gastrointestinal surgeries; elevated levels of GLP-1 in response to rapid presentation of nutrients to the distal jejunum (1)


  • Complex AR/AD mutations on ABCC8 and KCJN11 genes on chromosome 11 have been found in focal and diffuse NB (2).
  • More recent discoveries:
    • HADH1: Studies have shown good response with diazoxide (AR).
    • GK: poor response with diazoxide (AD)
    • GLUD1: associated with high ammonia levels, also called HI/HA syndrome (AD)
    • SLC16A1
    • HNF4A: has shown spontaneous resolution in a few cases (3)

Risk Factors

  • Infants/children: likely a genetic predisposition to this disorder
  • Adults: NB may also be genetically linked. However, there has been an association with gastric bypass surgery (1).

General Prevention

  • Genetic counseling may be of benefit to families affected by this disease. No clear guidelines exist for preconception genetic counseling.
  • Adults who are considering gastric bypass surgery should be cautioned.

Commonly Associated Conditions

  • Insulinoma (most common)
  • Teratomas
  • MEN1 syndrome
  • Glucagonoma
  • VIPoma
  • Neuroblastoma

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