A DIAGNOSIS of an insulin-secreting tumor is tenable when the clinical symptom-complex conforms with the criteria set forth in Whipple's triad. These criteria are as follows: ( 1 ) signs and symptoms of insulin shock usually progressive, frequently induced by fasting or exercise; (2) repeated fasting bloodsugar concentrations below 50 mg. per 100 cc, and (3) symptomatic relief by dextrose administration.
More than 400 cases of hypoglycemia due to pancreatic adenoma are reported in the literature, in half of which surgical treatment was employed. In about 45% of the patients explored, no tumor could be located by the surgeon. In more than one-half of these cases in which the surgeon did not find the tumor but proceeded with a subtotal pancreatectomy, the resected specimen was histologically normal. The over-all cure rate in patients is about 40% when the surgeon, in spite of finding no tumor, performs a subtotal pancreatic resection.1