SUN-539 A Sweet Deception: Normoglycemic HbA1c Masking Complex Glucose Dysregulation In A Patient With Pancreatic Lesions And Hematologic Pathology: A Case Report

Abstract Disclosure: J.C. Ramos Cardona: None. J. Gilmore: None. S. Martinez: None. Pancreatic neuroendocrine tumors (pNETs) and intraductal papillary mucinous neoplasms (IPMNs) are increasingly recognized for their complex metabolic and systemic manifestations. These lesions can impair both endocrine and exocrine pancreatic function, sometimes contributing to glucose dysregulation, even in the absence of overt diabetes. This case contributes to the growing literature exploring nontraditional markers of glycemic control in patients with pancreatic pathology and systemic comorbidities. We present a 59-year-old female with a history of autoimmune disease presented with persistent fatigue and glucose variability despite adherence to a ketogenic diet and pharmacologic therapy. Notably, her hemoglobin A1c remained within normal limits, masking ongoing hyperglycemia. Continuous glucose monitoring (CGM) and an oral glucose tolerance test (OGTT) revealed significant postprandial hyperglycemia, confirming impaired glucose metabolism. Imaging showed multifocal cystic pancreatic lesions with increased uptake on DOTA-TATE PET, raising concern for pNET. Laboratory workup revealed elevated ferritin levels and the presence of clonal hematopoiesis of indeterminate potential (CHIP), further complicating the clinical picture. The patient was diagnosed with impaired glucose tolerance, likely multifactorial in origin, involving suspected pNET/IPMN, systemic inflammation, and CHIP associated hematologic changes. A multidisciplinary team: including endocrinology, hematology, and oncology contributed to guide further investigation and longitudinal management. This case highlights the limitations of hemoglobin A1c in select populations and supports the use of CGM and OGTT in evaluating glycemic control. It also highlights the value of a multidisciplinary approach in diagnosing and managing atypical metabolic presentations involving overlapping endocrine, neoplastic, and hematologic processes. Presentation: Sunday, July 13, 2025