7396 IGF-2 Induced Hypoglycemia Associated with Metastatic Hepatocellular Carcinoma

Disclosure: F. Benyaminov: None. V. Cascio: None. A.G. Sinha: None. Background: Non-islet-cell tumor hypoglycemia (NICTH) is a rare entity caused by tumoral secretion of IGF-2 and is associated with a wide variety of tumors. The diagnosis is made based on serum levels of IGF-1, IGF-2, and/or pro-IGF-2. Unfortunately, due to the limited access to testing in many laboratories, this pathology is often missed. We present a case of IGF-2 mediated hypoglycemia in a patient with metastatic HCC. Clinical case: A 31-year-old man with a remote history of hepatitis B infection and recently diagnosed liver and lung lesions, likely metastatic in etiology, presented to the ED with weakness, tremors, and diaphoresis. He reportedly recorded a POC glucose level of 38 mg/dL at home. Serum glucose levels in the ED confirmed severe hypoglycemia with a serum glucose level of 50 mg/dL. Laboratory workup for insulin-mediated hypoglycemia was negative, including serum insulin (<0.4 uU/mL, n 2.6-24.9 uU/mL), proinsulin (0.7 pmol/L, n 0-10 pmol/L), C-peptide (0.1 ng/mL, n 1.1-4.4 ng/mL), BHB (0.0mmol/L), and insulin antibodies (<5.0 uU/mL) in the setting a serum glucose of 48 mg/dL. Thyroid function was normal, adrenal insufficiency was ruled out, and a sulfonylurea panel was negative. Given the likely presence of metastatic cancer, NICTH was suspected. Laboratory evaluation including IGF-2 (644 ng/mL, n 333-987 ng/mL) and IGF-1 (42 ng/mL, n 82-244 ng/mL) was consistent with IGF-2 mediated hypoglycemia, due to IGF-2:IGF-1 ratio of 14, where a ratio >10 is nearly diagnostic (1). Further laboratory workup was consistent with chronic hepatitis B, and a CT scan of the chest, abdomen, and pelvis confirmed numerous liver and lung lesions. A liver biopsy was performed with pathology demonstrating HCC. Initial treatment for hypoglycemia consisted of IV dextrose-containing fluids, with improvement of hypoglycemia. In preparation for discharge, non-pharmacological treatments were initially trialed. There have been case reports where patients were successfully treated for NICTH with cornstarch. Thus, the patient was then started on 30g of cornstarch daily, however they were unable to tolerate treatment due to nausea and the hypoglycemia persisted. The patient was instructed to eat frequent, high-carbohydrate meals including a bedtime snack which also failed to improve hypoglycemia. Subsequently, the patient was started on oral prednisone. They were eventually discharged on a dose of 20mg prednisone twice per day after achieving normoglycemia. Conclusion: NICTH due to tumoral secretion of IGF-2 is a rare cause of hypoglycemia that should be considered when labs reveal a non-insulin mediated etiology in the setting of malignancy. 1. Rana P, Kim B. A Unique Case of IGF-2 Induced Hypoglycemia Associated with Hepatocellular Carcinoma. Case Rep Endocrinol. 2019 Oct 13;2019:4601484. Presentation: 6/1/2024