Nonislet Cell Tumor Hypoglycemia: A Rare Paraneoplastic Syndrome.

Nonislet cell tumor hypoglycemia (NICTH) is a rare and underreported cause of hypoglycemia due to excessive production of insulin-like growth factor 2 (IGF-2) and its intermediate forms, which activate the insulin receptor. Typically, certain malignancies can cause NICTH, usually as a paraneoplastic syndrome. Diagnosis requires a raised IGF-2/IGF-1 ratio. Surgery forms the cornerstone of management, while glucocorticoids are an alternative when surgery is not possible. We present a unique case of a 27-year-old male, who was a follow-up case of chronic hepatitis B infection and presented with a gall bladder fossa mass and recurrent, severe episodes of hypoglycemia. Workup revealed low insulin and C-peptide and suppressed IGF-1 with normal pituitary function. Clinicians should consider the possible diagnosis of NICTH when laboratory and immunohistochemical (IHC) data do not support more common causes, such as insulinoma.