A 59-year-old woman with a history of ovarian cancer and hypertension, with recurrent episodes of hypoglycemia and weight gain. Laboratory studies were compatible with hypoglycemia due to endogenous hyperinsulinism. Imaging showed a 19 mm hypervascularized nodule in the head of the pancreas, and echoendoscopy showed a 12 mm homogeneous lesion dependent on the neck and head of the pancreas. He received treatment with diazoxide and continuous glucose monitoring (CGM), presenting episodes of hypoglycemia in the controls. Whipple surgery was performed and the pathological report was insulinoma. She had a favorable evolution and post-surgery CGM with no evidence of hypoglycemia; on the contrary, she presented hyperglycemia in the follow-up.