Insulinoma in a Patient with Type 2 Diabetes: A Case Report

ABSTRACT Objective: To describe a case of insulinoma in a patient with pre-existing type 2 diabetes mellitus. Methods: We report a case, with clinical, biochemical, and imaging findings, and give a literature review. Results: The most common causes of recurrent hypoglycemia in a patient with diabetes mellitus are insulin excess and use of insulin secretagogues. If these are completely ruled out, other causes must be considered. The co-existence of diabetes mellitus and insulinoma is very rare, with less than 40 cases reported in the literature. We report the case of a 66-year-old woman with obesity, hypertension, and type 2 diabetes mellitus treated with premixed insulin, who was diagnosed with an insulinoma in the setting of a 6-month history of severe recurrent hypoglycemia that persisted despite discontinuation of insulin therapy. A computed tomography of the abdomen revealed a 14-mm tumor in the pancreatic tail that was removed through laparoscopic distal pancreatectomy. Histopathologic examination co...