A 34-year-old man has recurrent episodes of sweating, tremor, confusion relieved by eating. During a supervised fast he develops plasma glucose of 38 mg/dL with inappropriately elevated insulin and C-peptide levels. The most likely diagnosis is:
- A Gastrinoma
- B Insulinoma ✓
- C Glucagonoma
- D Somatostatinoma
Correct answer: B. Insulinoma
Explanation
The combination of neuroglycopenic symptoms, biochemical hypoglycaemia, and relief with glucose constitutes Whipple's triad, and suppressed counter-regulatory hormones with raised insulin and C-peptide during a supervised 72-hour fast establishes endogenous hyperinsulinism, most often from a benign solitary insulinoma. Gastrinoma causes refractory peptic ulceration, glucagonoma causes diabetes and necrolytic migratory erythema, and somatostatinoma causes steatorrhoea and gallstones.
Reference: Schwartz's Principles of Surgery, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.