Paraneoplastic hypoglycemia as the initial presentation of a pancreatic neuroendocrine tumor

BACKGROUND: Hypoglycemia is a relevant and rare clinical condition in non-diabetic patients, particularly when associated with neoplasms. CASE PRESENTATION: This case report describes an 80-year-old woman with no significant medical history who presented to the emergency department with marked asthenia and a capillary blood glucose level of 37 mg/dL. During hospitalization, recurrent hypoglycemic episodes were documented, with suppressed insulin and C-peptide levels. Abdominal computed tomography revealed two pancreatic lesions with extensive hepatic metastases. Liver biopsy confirmed a well-differentiated pancreatic neuroendocrine tumor with a Ki-67 index of 3%. Laboratory evaluation revealed markedly suppressed IGF-1 levels and an elevated IGF-2:IGF-1 ratio, consistent with non-islet cell tumor hypoglycemia (NICTH). The patient responded well to prednisolone therapy and was subsequently discharged. She was then referred to the Oncology department and started on octreotide therapy. CONCLUSION: NICTH is a rare and often underdiagnosed paraneoplastic syndrome with significant clinical implications. This case report highlights the importance of considering this entity in patients with unexplained hypoglycemia and emphasizes the crucial role of laboratory and imaging studies in identifying the underlying malignancy.