RESUMEN
Insulinomas are islet cell tumors of the pancreas that produce hypoglycemia due to inappropriate insulin secretion. They appear generally as solitary adenomas, and less commonly as multifocal microadenomas or malignant insulinomas. Their incidence is approximately one case per 1 million population per year, and they appear mostly in patients above thirty years old. They are mainly situated in the pancreas tail or body. The diagnosis is based on the symptoms related to hypoglycemia, a blood glucose level under 50 mg% and high levels of fast insulin and C-peptide. Selective angiography is the best preoperative procedure to localize the tumor. Occult adenomas, which cannot be represented by preoperative imaging diagnosis, are detectable through intraoperative methods. Primary treatment of insulinoma is surgical resection of the tumor. When it fails or is contraindicated, medical treatment is considered. We present a case of a patient with an insulinoma, who has had excellent response to medical treatment, and we review the clinical manifestations, diagnostic methods and different types of treatment for such a rare disease