Clinical profile of insulinoma: analysis from a tertiary care referral center in India

Objective To describe the clinical presentation, localization techniques, surgical procedures and outcome in patients with insulinoma. Methods Retrospective analysis of case records of patients diagnosed with insulinoma between January 1993 and June 2009 at a tertiary-care hospital was done. Seventeen patients underwent diagnostic 72-h fast. The sensitivity of computed tomography (CT) of pancreas was judged using intraoperative findings as the gold standard. Results Twenty-six patients (19 women) with mean age 42.2 years (median age 39.5 years) with biochemical/imaging evidence of insulinoma were included. All patients who underwent 72-h fast developed symptomatic hypoglycemia within 48 h. The sensitivity and positive predictive value (PPV) of CT of pancreas was 68.4% and 92.8%, respectively. Twenty patients underwent surgery, of whom four were operated on without preoperative localization. Four patients had recurrence of symptoms. Of the six patients who were not operated upon, the lesion was localized in four. Conclusion This audit shows that all patients with insulinoma develop hypoglycemia within 48 h of fasting. CT of pancreas localizes the lesion in two thirds of cases and would be a useful initial investigation in patients with suspected insulinoma.