Background: Hypoglycemic episodes are infrequent in individuals without a history of diabetes mellitus or bariatric\nsurgery. When hypoglycemia does occur in such individuals, an uncommon but important diagnosis to consider is\nnon-islet cell tumor hypoglycemia (NICTH). We report a case of NICTH associated with paraneoplastic insulin-like\ngrowth factor-2 (IGF-2) production and review current relevant medical literature.\nCase presentation: A 60 year old male with no relevant past medical history was referred to the endocrinology\nclinic with 18 month history of episodic hypoglycemic symptoms and, on one occasion was noted to have a\nfingerstick glucose of 36 mg/dL while having symptoms of hypoglycemia. Basic laboratory evaluation was\nunrevealing. Further evaluation however showed an elevated serum IGF-2 level at 2215 ng/mL (reference range\n411ââ?¬â??1248 ng/mL). Imaging demonstrated a large right suprarenal mass. A right nephrectomy with resection of the\nmass demonstrated a malignant solitary fibrous tumor. Post resection, the patientââ?¬â?¢s IGF-2 levels normalized and\nhypoglycemic symptoms resolved.\nConclusion: Due to the structural and biochemical homology between IGF-2 and insulin, elevated levels of IGF-2\ncan result in hypoglycemia. A posttranslational precursor to IGF-2 known as ââ?¬Å?big IGFââ?¬Â also possesses biologic activity.\nReview of recent reported cases of NICTH identified widespread anatomic locations and varied pathologic diagnoses of\ntumors associated with paraneoplastic production of IGF-2 causing hypoglycemia. Definitive management of\nhypoglycemia associated with paraneoplastic production of IGF-2 consists of resection of the tumor responsible\nfor IGF-2 production. Accumulating literature provides a firm basis for routine IGF-2 laboratory evaluation in\npatients presenting with spontaneous hypoglycemia with no readily apparent cause.
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