Enucleation of a solitary pancreatic tail insulinoma: a case report and review of the literature

Abstract

Introduction: Insulinomas are the most common pancreatic neuroendocrine tumors. They secrete insulin and result in endogenous hyperinsulinaemic hypoglycemia. The diagnosis of insulinoma was classically based on the fulfillment of Whipple’s triad; hypoglycaemia (plasma glucose <50mg/dL), neuroglycopaenic symptoms, and the prompt relief of such symptoms with the administration of glucose. Preoperative localization of the insulinoma will help to plan the type of surgery necessary, either enucleation or pancreatic resection, and also decide on the approach, either open or laparoscopic. Case description: A 53-year-old farmer presented with neuroglycopenia symptoms with biochemical evidence of endogenous hyperinsulinaemic hypoglycemia during the mixed meal test. Imaging evidence in the form of CT and MRI showed a benign, approximately 1cm, solitary pancreatic tail insulinoma. Intraoperative ultrasonography confirmed the findings and the patient underwent enucleation of the tumor. Histology revealed a grade 2 pancreatic neuroendocrine tumor with confirmation of an insulinoma on immunohistochemistry. Conclusion: Pancreatic insulinomas, a rare pancreatic tumor, the commonest of the pNET present with neuroglycopenia. Diagnosis entails biochemical confirmation of endogenous hyperinsulinaemic hypoglycemia on a 72-hour prolonged fasting test. Noninvasive imaging in the form of CT as the first line, followed by MRI is used for localization and assessment of resectability. EUS and ASVS are additional invasive imaging in diagnostic difficulty. Enucleation and intraoperative ultrasonography is the treatment of choice for small, benign, pancreatic insulinomas.