Clinical characteristics and incidence of glucose metabolism disorders during the follow-up of surgically treated insulinomas.

Purpose: Insulinomas are pancreatic endocrine tumors characterized by hypoglycemia resulting from hypersecretion of insulin. The long-term impact of surgical treatment of insulinomas, particularly the risk of glucose metabolism disorders, remains largely unknown.

Methods: We retrospectively evaluated all patients with insulinoma submitted to surgery at Centro Hospitalar Universitário de São João (Porto, Portugal) between 1980 and 2016. We evaluated baseline characteristics of patients at presentation, imaging evaluation, surgical treatment, characteristics of the tumors, perioperative complications, disease remission, and long-term follow-up and metabolic outcomes.

Results: Twenty-eight patients with insulinomas submitted to surgical treatment were included. Sixty-one percent were female, and the average age was 46.4 years. The most reported symptoms were confusion (72%) and diaphoresis (56%). The most used imaging technique was abdominal CT (72%), and the test with the highest percentage of positive results was endoscopic ultrasound (80%). The most used surgical procedure was partial pancreatic resection (71%). The mean tumor diameter was 2.1 cm and 11% of the tumors had lymph node involvement at diagnosis. Pancreatic fistula was the most common postoperative acute complications (21%). After surgery, patients were followed for a median time of 80 months (25th-75th percentile: 20-148 months). Eight patients (32%) developed glucose metabolism disorders (seven developed diabetes and one prediabetes). One of these patients developed albuminuria, and no macrovascular complications were observed during the follow-up.

Conclusions: Disorders of glucose metabolism are a frequent complication during follow-up of surgically treated insulinomas. The prevention, early diagnosis, and treatment of diabetes should be a priority in the follow-up of these patients.