Insulin-secreting tumor of the pancreas. Report of a case with an untoward response to tolbutamide and with a study of the possible mechanism of postoperative hyperglycemia.

RESPONSE of the blood sugar after intravenous injection of tolbutamide has recently been recommended1 as a procedure of diagnostic value in patients suspected of harboring an insulin-secreting tumor. The use of a hypoglycemic agent in a patient who may already have low blood sugar levels obviously carries certain risks. To emphasize these, we wish to call attention to our experience with a patient who had an islet-cell adenoma. In the same patient a sample of blood from a pancreatic vein was obtained at operation shortly after removal of the tumor. The result of assay for insulinlike activity in this sample . . .