A 25-year-old female presents with episodes of bizarre behavior, memory lapse, and unconsciousness. She also demonstrated previously episodes of extreme hunger, sweating, and tachycardia. During one of these episodes, her blood sugar was tested and was found to be 40 mg/dL. Which of the following would most appropriately indicate a diagnosis of insulinoma?
The characteristic features of insulinomas include: (a) hypoglycemic symptoms; (b) blood glucose <50 mg/dL during the symptomatic episodes; and (c) relief of symptoms by intravenous injection of glucose (Whipple's triad). Diagnosis is confirmed by demonstration of fasting hypoglycemia in the presence of inappropriately elevated levels of insulin in the blood. A ratio of plasma insulin/glucose >0.3 is diagnostic. Circulating levels of C-peptide are usually elevated in patients with insulinoma but not in patients with such other causes of hypoglycemia as tumors of mesenchymal origin and liver tumors. Patients who surreptitiously administer insulin develop insulin antibodies.
Demonstration of insulin antibodies in blood
Abnormal glucagon level
CT of the pancreas showing a mass
Hypoglycemia during a symptomatic episode with relief of symptoms by intravenous glucose
Pancreas