SUN-302 Hypoglycemia in Malignancy: A Rare Case of Metastatic Colon Adenocarcinoma Presenting as Hypoglycemia

Abstract Disclosure: M. Romanovschi: None. N. Raja: None. Y. Hu: None. R. El-Hajj: None. Introduction: Nonislet cell tumor hypoglycemia (NICTH) is a rare but significant paraneoplastic syndrome characterized by hypoglycemia in patients with certain types of tumors that do not arise from the insulin-producing islet cells of the pancreas. Case: This is a case of a 74-year-old male with a past medical history of type 2 diabetes who presented with altered mental status in the setting of recurrent symptomatic hypoglycemia for two weeks. He had noted episodes of symptomatic hypoglycemia for one month with his PCP who decreased his Jardiance dose at the time. The morning of admission his family found him somnolent and confused with BG of 20 mg/dL (70-99 mg/dL). He was started on a continuous D5 infusion. Lab work showed blood glucose of 63 mg/dL (70-99 mg/dL), C-peptide 0.34 ng/mL (0.70-4.10 ng/mL), insulin 0.5 mU/L (1.9-23.0 mU/L), proinsulin level of <4.0 pmol/L (< OR = 18.8 pmol/L ), beta-hydroxybutyrate level 0.05 mmol/L (<0.28 mmol/L), IGF-1 <10 ng/mL (34-245 ng/mL), IGF-2 110 ng/mL (267-616 ng/mL), and cortisol of 9.7 ug/dL (6.7-22.6 ug/dL). The high IGF2/IGF1 ratio (normal <3:1) supports the diagnosis of NICTH. He was started on steroid replacement therapy given evidence of inappropriately low cortisol levels concerning for adrenal insufficiency. Given persistent hypoglycemia, D5 was increased in concentration to D70. A complete metabolic panel also revealed newly elevated liver enzymes. CT showed a large splenic flexure mass and multiple hepatic lesions concerning for metastasis. Colonoscopy with biopsy confirmed metastatic adenocarcinoma. He continued to suffer from severe hypoglycemia and started on continuous octreotide infusion. Despite these therapies he continued to suffer from persistent hypoglycemia. He was started on chemotherapy with capecitabine twice daily, however given the extent of disease he ultimately transitioned to comfort care and passed one month later. Discussion: This patient presented with new onset refractory severe hypoglycemia in the setting of stage IV colon cancer. The etiology of hypoglycemia was due to nonislet cell tumor hypoglycemia (NICTH). NICTH is primarily reported to be associated with large, often mesenchymal tumors, such as fibrosarcomas or hepatocellular carcinoma. In this case, the patient’s NICTH was caused by an elevated IGF2 due to overproduction from his underlying metastatic colon cancer leading to disruption of glucose homeostasis and excessive glucose consumption. The management of NICTH relies on treatment of the underlying tumor (including surgical resection, chemotherapy, or targeted therapies, depending on the tumor type) along with supportive treatment for hypoglycemia. The treatment of NICTH can be challenging without successful treatment of the underlying tumor. Supportive therapies include aggressive nutrition support and medications such as octreotide, corticosteroids, diazoxide can be tried. Presentation: Sunday, July 13, 2025