A 40-year-old woman develops light-headed episodes associated with sweating, palpitations, and hunger whenever she misses a meal. Her physical examination is normal, and she is not taking any medications. On one such episode, while in hospital, her blood glucose level was 30 mg/dL and the symptoms resolved with giving her juice. Which of the following is the most likely diagnosis?
High-Yield Explanation
Classification of hypoglycemia includes spontaneous causes such as reactive or fasting hypoglycemia and pharmacologic or toxic causes. The diagnosis of insulinoma is most certain when Whipple's triad is fulfilled: symptoms consistent with hypoglycemia, low plasma glucose, and relief of symptoms with elevation of plasma glucose to normal.