Endocrine Abstracts

Insulinomas are predominantly benign pancreatic neuroendocrine tumors presenting with hyperinsulinemic hypoglycemia. Surgical resection is currently the standard treatment for pancreatic insulinoma, but other treatment options, such as oral medication with diazoxide may be necessary for symptomatic patients who are not candidates for surgical resolution or for those who need bridging therapy till the surgical intervention. We present the case of a 54-year-old man who was admitted to our Endocrinology Department with a 2-year history of epileptic seizures of unknown origin. The seizures occurred, when he was on a weight loss diet. Neurological workup (including a negative MRI of the head and EEG) could not define the etiology of the seizures. Laboratory studies showed hypoglycemia with hyperinsulinemia almost every 3 hours. An endosonographic investigation was planned to identify the suspected insulinoma, but this got delayed because the patient was diagnosed with SARS-CoV-2 infection. He became subfebrile, developed lethargy and cough, but did not require oxygen supplementation. Chest CT showed pneumonia and abdominal CT revealed a 17 × 17 mm lesion in the pancreatic tail, which was believed to be consistent with the radiological manifestation of an insulinoma. Surgical removal of the tumor was planned following recovery from COVID-19. In the meantime, for symptomatic treatment he was started on diazoxide therapy. To reveal asymptomatic hypoglycemia and to take advantage of the hypoglycemia alert function of the device, the tissue glucose level of the patient was real-time monitored with continuous glucose monitoring system (CGMS). CGMS was started 1.5 days before the introduction of diazoxide therapy and was continued for a total of 6 days. The patient was discharged with diazoxide to be used during recovery from COVID-19. After his recovery the surgical resection was successfully performed. The patient was discharged without diazoxide therapy and did not show hypoglycemic tendency. Hypoglycemia increases cardiovascular mortality, therefore avoidance or prompt treatment of hypoglycemic episodes is imperative in patients with insulinomas, until definitive surgical intervention can be performed. Our case highlights that CGMS can be successfully used to detect asymptomatic hypoglycemia in patients with insulinoma, and can also confirm the response to medical therapy.