PSUN279 Refractory Hypoglycemia in the Setting of Incidental Urothelial Carcinoma

INTRODUCTION: Hypoglycemia is uncommon in individuals who do not have drug-treated diabetes mellitus. In such patients, differentials include cortisol deficiency, insulinomas or autoantibodies against insulin/ insulin receptor. Malignancy related causes include non-islet cell tumors and extensive liver infiltration. This case highlights the workup of hypoglycemia in a patient with an incidental diagnosis of urothelial cancer. CLINICAL CASE: We present a 62 year old male who was assessed by the EMS at home for difficulty in arousal and facial drooling. Initial assessment found him to have a random glucose of 26mg/dL. His glucose was corrected with dextrose and the EMS left. Nine hours later the EMS was called again strange behavior, where he was found again to be hypoglycemic (19mg/dL). Glucagon and dextrose was administered and he was transported to the ED. His finger stick glucose on arrival was 26mg/dL. Endocrine history is primary hypothyroidism only. Other significant past medical history was a retroperitoneal mass seen on routine surveillance imaging one month ago, after being treated for renal cell carcinoma with right partial nephrectomy 10 years ago. On physical exam, vitals were stable, he was alert and oriented. Other physical examination findings were normal. His BMI was 35.23 kg/m(2). Relevant initial labs were venous blood glucose 43 mg/dL, TSH 11.4 uU/mL and T4 was 1.1 ng/dL. Blood ethanol level was undetectable. Despite receiving multiple ampules of 50% dextrose and continuous 10-20% dextrose IV infusion he continued to be hypoglycemic and therefore was admitted to the ICU. The initial management course was as follows: He was started on octreotide infusion and given scheduled diazoxide for persistent hypoglycemia with no improvement. For suspected non-islet cell tumor, he was started on glucagon infusion, however there was no significant correction. Calorie intake was monitored and increased by nutrition and was subsequently given enteral/ parenteral nutrition. He was also started on hydrocortisone 50mg every 8 hours. Endocrine investigations were as follows: Insulin, C-peptide, urine sulfonylureas and ß-hydroxybutyrate were undetectable, proinsulin 2.9 pmol/L (ref <= 8.0 pmol/L), Insulin antibody negative, IGF-1 44 ng/mL (ref 49-214 ng/mL), IGF-2 129 ng/dL (IGF-II/IGF-I < 10). Random cortisol was 26 µg/dL. Investigations for the retroperitoneal mass were as follows: a biopsy showed high grade invasive urothelial carcinoma. MRI abdomen showed extensive and diffuse infiltrative metastatic liver disease without evidence of pancreatic endocrine tumor. The final diagnosis was determined to be due to extensive tumor infiltration in the liver. His condition deteriorated during ICU stay and comfort measures were initiated; subsequently he deceased. CONCLUSION: The causes of hypoglycemia in patients with known tumors include extensive tumor infiltration and nonislet cell tumors, two uncommon causes of hypoglycemia. Differentiating between nonislet tumor secretion and direct tumor infiltration is based on IGF-2 level and the IGF-2/IGF-1 ratio. Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.