Changing Insulinoma Management Due to Incidentally Discovered Metastasis: A Case Report

BACKGROUND Hypoglycemia is rare in individuals without drug-treated diabetes mellitus. In a seemingly well individual, the differential diagnosis of hypoglycemia narrows to 2 major categories: 1) accidental, surreptitious, or intentional hypoglycemia, or 2) endogenous hyperinsulinism (EHH). Insulinomas are the most common cause of EHH. Localization of insulinomas can be challenging, as most tumors are less than 2 cm in size and may be present in any part of the pancreas. In fact, almost 30% of neuroendocrine tumors (NET) cannot be located preoperatively by traditional imaging techniques such as computerized tomography (CT) or magnetic resonance imaging (MRI). CASE REPORT This report describes a case of metastatic insulinoma in a patient with a complex medical history. CT with contrast of the abdomen identified 1 lesion located in the pancreas body. Endoscopic ultrasound (EUS) identified an additional 3 to 4 hypoechoic lesions in the pancreatic neck and body. 68-Gallium Dotatate scanning identified 3 distinct lesions within the pancreas and a right posterior rib sclerotic lesion. CONCLUSIONS Reliance upon traditional imaging techniques (CT/MRI) for tumor localization would not have identified the multifocal pancreatic lesions and the metastatic bone lesion. Accurate identification of multifocal, metastatic insulinomas requires multiple imaging modalities, including first-line non-invasive imaging (CT or MRI) followed by second-line imaging (EUS or nuclear imaging).