Endocrine Abstracts

Introduction: Insulinomas are the most frequent cause of hypoglycemia and the most common functional endocrine pancreatic tumors. Whipple triad is often present and should alert to the diagnosis.

Case report: A 36-year-old male was admitted in the emergency room with loss of consciousness, diaphoresis and blurred vision, and hypoglycemia (50 mg/dl). The patient recalled recurrent symptoms of diaphoresis, tremors and palpitations, sometimes with loss of consciousness and incontinence of urinary sphincters, for the past 4 months, having been diagnosed with epilepsy and medicated with anticonvulsive drugs. This symptoms were associated with weight gain, occurred before meals and were relieved with eating carbon hydrates. He had no family history of endocrine disease. Prolonged supervised fasting test was applied and led to symptomatic hypoglycemia with hyperinsulinemia (blood glucose 40 mg/dl, plasma insulin 68.7 μIU/ml and C-peptide 7.07 ng/ml). Other hormonal studies were normal, rejecting the diagnosis of multiple endocrine neoplasia. He maintained severe hypoglycemia despite glucose fluid administration and nutritional adequate plan, and medical treatment was necessary with octreotide 300 mg/day and diaxozide 900 mg/day. Abdominal magnetic resonance demonstrated a well-defined enhanced lesion in the tail of the pancreas measuring 14 mm. Nodule enucleation was performed by laparoscopy and pathological examination revealed an encapsulated pancreatic mass measuring 17×14×15 mm. Mitotic index was <2 per 10 CGA and proliferation index ki-67 was estimated <2%. Immunohistochemically, tumor cells showed a positive staining for insulin, synaptophysin and cromogranine. Shortly after surgical treatment, glucose level increased to normal range. The patient was discharged without any hypoglycemic symptoms after 7 days.

Conclusion: The diagnosis of insulinoma may be challenging due to its rarity and variable presentation. Other diseases, such as neurologic, may be considered first, but it’s important to contemplate the diagnosis since chronic and severe hypoglycemia can be fatal and the surgery is usually curative.