Insulinoma
Basics
Description
- Neoplasm of the pancreatic β cells of the islets of Langerhans leading to hyperinsulinemia. Pancreatic β cells manufacture proinsulin, which is then cleaved into insulin and C-peptide before secretion.
- Most common functional (insulin producing) tumor of the pancreas
- 90% are located within the pancreas.
- Usually small with 90% <2 cm; suspect malignant insulinoma if tumor is >4 cm.
- Symptoms due to hypoglycemia and concomitant cerebral glucose deprivation
- Diagnosis of insulinoma is often delayed due to vague and unusual presentation of neuroglycopenic symptoms.
- Hypoglycemic episodes are irregular, recurrent, and tend to increase in frequency and severity over time.
- Definitive management consists of surgical resection.
- Synonym(s): β-cell tumor; β-cell adenoma; nesidioblastoma
Epidemiology
Incidence
- 3 to 4 cases per 1 million person-years
- 10% malignant, 10% multiple tumors (1)
- Two major categories: sporadic (>90%) and multiple endocrine neoplasia type 1 (MEN1) syndrome (5–10%); etiology dictates treatment approach (2).
Prevalence
The prevalence of insulinoma is 0.4% (4).
Genetics
Risk Factors
MEN1 syndrome only known risk factor (1)
Commonly Associated Conditions
MEN1 syndrome (1)
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Citation
Domino, Frank J., et al., editors. "Insulinoma." 5-Minute Clinical Consult, 33rd ed., Wolters Kluwer, 2025. Medicine Central, im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688711/all/Insulinoma.
Insulinoma. In: Domino FJF, Baldor RAR, Golding JJ, et al, eds. 5-Minute Clinical Consult. Wolters Kluwer; 2025. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688711/all/Insulinoma. Accessed November 6, 2024.
Insulinoma. (2025). In Domino, F. J., Baldor, R. A., Golding, J., & Stephens, M. B. (Eds.), 5-Minute Clinical Consult (33rd ed.). Wolters Kluwer. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688711/all/Insulinoma
Insulinoma [Internet]. In: Domino FJF, Baldor RAR, Golding JJ, Stephens MBM, editors. 5-Minute Clinical Consult. Wolters Kluwer; 2025. [cited 2024 November 06]. Available from: https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688711/all/Insulinoma.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC
T1 - Insulinoma
ID - 1688711
ED - Domino,Frank J,
ED - Baldor,Robert A,
ED - Golding,Jeremy,
ED - Stephens,Mark B,
BT - 5-Minute Clinical Consult, Updating
UR - https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688711/all/Insulinoma
PB - Wolters Kluwer
ET - 33
DB - Medicine Central
DP - Unbound Medicine
ER -