Insulinoma is a rare pancreatic neuroendocrine tumor. Overproduction of insulin and associated hypoglycemia are hallmark features of this disease. Diagnosis can be made through demonstration of hypoglycemia and elevated plasma levels of insulin or C-Peptide. Metastatic disease can be detected through computerized tomography (CT) scans, magnetic resonance imaging (MRI), and positron emission tomography (PET)/CT. Somatostatin receptor scintigraphy can be used not only to document metastatic disease but also as a predictive marker of the benefit from therapy with radiolabeled somatostatin analog. Unresectable metastatic insulinomas may present as a major therapeutic challenge for the treating physician. When feasible, resection is the mainstay of treatment. Prevention of hypoglycemia is a crucial goal of therapy for unresectable/metastatic tumors. Diazoxide, hydrochlorothiazide, glucagon, and intravenous glucose infusions have been used for glycemic control yielding temporary and inconsistent results. Sandostatin and its long-acting depot forms have occasionally been used in the treatment of Octreoscan-positive insulinomas. Herein, we report a case of metastatic insulinoma with very difficult glycemic control successfully treated with the radiolabeled somatostatin analog lutetium (177LU). 1. Introduction Insulinoma is a rare pancreatic neuroendocrine tumor . Overproduction of insulin and associated hypoglycemia are hallmark features of this disease. Diagnosis can be made through demonstration of hypoglycemia and elevated plasma levels of insulin or C-peptide. Confirmation of neuroendocrine nature of the tumor by immunohistochemistry requires chromogranin and synaptophysin positivity. Metastatic disease can be detected through computerized tomography (CT) scans, magnetic resonance imaging (MRI), and positron emission tomography (PET)/CT . Somatostatin receptor scintigraphy may be used not only to document metastatic disease but also as a predictive marker of benefit from therapy with radiolabeled somatostatin analog . The treatment of unresectable metastatic insulinoma is associated with prolonged hospitalization for intravenous glucose infusion. The management of recurrent hypoglycemia also encompasses the administration of diazoxide, hydrochlorothiazide, and glucagon. Sandostatin and its long-acting depot form (Sandostatin LAR) are an adjunct therapy to neuroendocrine tumors. There are a few reports of glycemic control in patients with insulinoma treated with radio labeled somatostatin analogs [4, 5]. The m-TOR inhibitor everolimus has been used
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