Severely Fluctuating Blood Glucose Levels Associated with a Somatostatin-Producing Ovarian Neuroendocrine Tumor

Context: Somatostatin-producing tumors are a rare type of neuroendocrine tumor. Their effects on blood glucose levels have been variously reported, and detailed reports have been scarce. Objective: The aim of this study was to identify the reasons for the extraordinary blood glucose fluctuations in a case with no previous history of diabetes. Patients and Methods: A 68-yr-old nondiabetic woman with an ovarian tumor was suffering from hyper- and hypoglycemia. Based on the results of an oral glucose tolerance test and continuous glucose monitoring, we speculated that the fluctuating blood glucose level was accompanied not only by a low insulin level but also by low counter-regulatory hormones levels, and that those broad hormonal suppressions were caused by a high somatostatin level produced in the ovarian tumor. We performed an oophorectomy and assessed the pathology of the tumor and changes in the blood glucose profile as well as hormonal levels postoperatively. Results: The blood glucose level was comple...