SAT141 A Case Of Non-islet Cell Tumor Hypoglycemia Which Was Ameliorated By Pazopanib Treatment

Disclosure: N. Yamamoto: None. M. Yamamoto: None. N. Kiyota: None. Y. Inaba: None. K. Kanie: None. S. Urai: None. M. Suzuki: None. Y. Sasaki: None. Y. Oi: None. Y. Tsujimoto: None. Y. Motomura: None. Y. Ohmachi: None. H. Bando: None. G. Iguchi: None. M. Nagao: None. I. Fukuda: None. H. Fukuoka: None. W. Ogawa: None. Introduction: Non-islet cell tumor hypoglycemia (NICTH) is a rare paraneoplastic syndrome caused by insulin-like growth factor II (IGF-II) hypersecretion from the tumors. It is characterized by incompletely processed big IGF-II with potent insulin-like activity. We present a case of NICTH complicated with solitary fibrous tumor (SFT) which was ameliorated with the administration of pazopanib, a multi-targeted tyrosine kinase inhibitor. Clinical Case: A 57-year-old man went into a coma and was hospitalized. His plasma glucose levels were 26 mg/dL, and he regained consciousness after glucose administration, leading to a diagnosis of hypoglycemic coma. Moreover, a contrast-enhanced CT scan showed multiple tumors in his liver and right kidney. He was referred to our hospital for further management. After 5 hours of fasting, he had a cold sweat, and his plasma glucose levels dropped to 32 mg/dL with suppressed serum insulin levels of 0.2 U/mL. Serum 3-hydroxybutyrate levels were as low as 21 μmol/L, and plasma glucose levels increased to 83 mg/dL after glucagon administration, suggesting an agent mimicking insulin. Percutaneous liver biopsy was performed, and the tumors were diagnosed with SFT. Immunoblotting for his serum showed big IGF-II, leading to a diagnosis of NICTH, and hypoglycemia due to hypersecretion of IGF-II. Due to multiple metastases, surgery was not indicated and pazopanib was administered. Hypoglycemia during the night was prevented by glucose infusion through the central venous port, and he was discharged. Three months later, when he was re-hospitalized for thrombophlebitis of the right jugular vein, hypoglycemia did not occur even after 10 hours of fasting and CT scan showed the necrotic change of the tumor. Two weeks later of pazopanib discontinuation due to the thrombogenic adverse effect, hypoglycemia recurred accompanied by the tumor enlargement. When the anticoagulation therapy regressed the thrombosis and pazopanib was re-administered, hypoglycemia improved reproducibly and remained stable for more than 2 years although the tumor showed gradual progression. Conclusion: This is the first case in which pazopanib was effective in suppressing NICTH associated with SFT. Presentation: Saturday, June 17, 2023