12315 Unveiling A Paraganglioma: Catecholamine-Induced Hyperglycemia Masquerading As Type 2 Diabetes Mellitus

Abstract Disclosure: S. Salman: None. M. Hussine: None. J. Tibaldi: None. Background: Excessive catecholamines have been demonstrated to exert adverse effects on insulin homeostasis and carbohydrate metabolism, potentially resulting in the onset of secondary DM. We present a case of a patient who had been previously misdiagnosed with T2DM for an extended period. Clinical Case: A 34-year-old woman with history of T2DM, HTN, and chronic tachycardia on beta blockers, presented with complaints of palpitations, headaches, and abdominal pain for two weeks. Upon admission, she was found to be in DKA, necessitating transient administration of insulin drip. Furthermore, she exhibited persistent tachycardia and intermittent episodes of hypertensive urgency. Notably, thyroid levels revealed euthyroidism. Although DKA resolved, her fasting blood sugar levels remained elevated and refractory to escalating insulin therapy. CT abdomen with contrast revealed a large enhancing mass in the RUQ. MRI abdomen confirmed an 8.1 cm heterogeneously enhancing T2 hyperintense mass located in the RUQ, abutting the right hepatic lobe, right adrenal gland, extrahepatic biliary ducts, and adjacent vessels. Given suspicions of a neuroendocrine tumor, she was transferred to the surgical service for tumor excision. Hormonal analysis revealed elevations in plasma metanephrines (620 pg/mL, n 0-88 pg/mL), plasma normetanephrines (9954 pg/mL, n 0-210.1 pg/mL), 24-hr urine normetanephrines (10,952 μg/24hr, n 110-720 μg/24hr) and 24-hr urine metanephrines (1406 μg/24hr, n 35-278 μg/24hr). Additionally, she exhibited elevated 24-hr urine epinephrine fraction (218 μg/g Cr, 0-20 μg/g Cr) and 24-hr urine norepinephrine fraction (2775 μg/g Cr, 0-45 μg/g Cr). Preoperatively, appropriate alpha and beta blockade were administered, followed by successful retroperitoneal tumor resection. Postoperatively, her glucose levels normalized without the need for further insulin therapy, and no episodes of hypoglycemia were reported. Histopathological examination of the excised mass revealed an 11 cm sympathetic paraganglioma with retention of SDHB staining. Genetic testing for SDHB, SDHD, VHL, and RET mutations is pending. Conclusion: This case underscores the potential oversight of pheochromocytomas and paragangliomas due to their nonspecific symptomatology, often mimicking more prevalent conditions, thereby presenting diagnostic challenges. The catecholamines secreted by these tumors can lead to both impaired insulin secretion and increased insulin resistance, resulting in clinically significant manifestations. The exact mechanism underlying the glycemic dysregulation remains controversial, necessitating further investigation through large-scale multicenter prospective studies to enhance understanding and inform diagnostic and therapeutic strategies for these tumors, which can manifest with severe and potentially fatal glycemic disturbances. Presentation: 6/1/2024