<prompt> Gold standard investigation for diagnosis of insulinoma -Blood glucose level less than 30 mg72 hrs fastingC peptide levels less than 32 rjmSerum insulin levels  <response>: Pathology of pancreatic endocrine tumor insulinoma. Specialty. Oncology. An insulinoma is a tumor of the pancreas that is derived from beta cells and secretes insulin. It is a rare form of a neuroendocrine tumor The diagnosis of insulinoma is suspected in a patient with symptomatic fasting hypoglycemia. The conditions of Whipples triad need to be met for the diagnosis of true hypoglycemia to be made: symptoms and signs of hypoglycemia, concomitant p 72 hrs fasting blood glucose level of 45 mgdL 2.5 mmolL or less, and reversibility of symptoms with administration of glucose. Ref Davidson edition23rd pg834 