METASTATIC MALIGNANT INSULINOMA IN A PATIENT WITH TYPE 2 DIABETES MELLITUS: CASE PRESENTATION AND LITERATURE REVIEW

Objective: To describe the occurrence of metastatic malignant insulinoma in a patient with preexisting type 2 diabetes mellitus. Methods: We present a detailed case report, with clinical, biochemical, and imaging findings, and summarize the data from 21 similar cases in the literature. Results: The occurrence of malignant insulinoma in a patient with preexisting diabetes is very rare and thus can be a diagnostic challenge. In our patient with type 2 diabetes, endogenous hyperinsulinism was confirmed by demonstrating elevated insulin and C-peptide levels during hypoglycemic episodes in the absence of sulfonylurea on a blood screen. Abdominal computed tomographic scan and magnetic resonance imaging revealed a pancreatic mass as well as metastatic lesions in the liver. The pancreatic mass was removed and confirmed to be a malignant insulinoma. This procedure was followed by disappearance of the hypoglycemic episodes as well as the diabetes for a few months. On follow-up, however, more metastatic lesions appe...