INS and hyperinsulinism: In a consensus report from the US Endocrine Society, the proposed criteria for the diagnosis of Insulinoma were as follows: endogenous hyperinsulinism documented by the finding of symptoms, signs, or both; with plasma concentrations of glucose <55 mg/dl (3.0 mmol/litre), insulin ≥ 3.0 μU/ml (18 pmol/litre), C-peptide ≥0.6 ng/ml (0.2 nmol/litre), and proinsulin ≥5.0 pmol/litre (45).