Insulinoma Differential Diagnoses

Updated: May 31, 2020
  • Author: Zonera Ashraf Ali, MBBS; Chief Editor: Neetu Radhakrishnan, MD  more...
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DDx

Diagnostic Considerations

Factitious hypoglycemia can occur in patients who have psychiatric disturbances or a need for attention and access to insulin or sulfonylurea drugs (eg, medical staff). [22] The triad of hypoglycemia, high immunoreactive insulin levels, and suppressed plasma C-peptide immunoreactivity is pathognomonic of exogenous origin. Insulin-induced hypoglycemia can be detected by a ratio of insulin to C-peptide that is greater than 1.0.

Hypoglycemia can occur after inadvertent ingestion of sulfonylurea due to patient or pharmacist error.

Autoimmune hypoglycemia is a rare disorder caused by the interaction of endogenous antibodies with insulin or the insulin receptor. [23] The condition is more common in Japan than in the United States or Europe. The syndrome may produce severe neuroglycopenic symptoms, making immunosuppressive therapy occasionally necessary. [17]

Nesidioblastosis is defined as hyperplasia of the islet cells causing hyperinsulinemic hypoglycemia. It is a predominantly neonatal disorder, although cases in adults have been reported recently. [24]

Noninsulinoma pancreatogenic hypoglycemia syndrome (NIPHS) is a condition in which pancreatic islet hyperplasia is present. [25] This is manifested with postprandial neuroglycopenia, a negative normal fasting test, negative pancreatic imaging results, and positive intra-arterial calcium stimulation of serum insulin.

Familial persistent hyperinsulinemia is manifested with inappropriately high insulin secretions seen in families with mutations in the glucokinase enzymes, glutamate dehydrogenase and short-chain3-hydroxyacyl1-CoA dehydrogenase.

Other causes for hypoglycemia include liver disease, endocrine deficiencies, extrapancreatic insulin-producing tumors (an insulin-secreting small-cell carcinoma of the cervix recently has been described), and pentamidine-induced hypoglycemia.