[Postoperative hypoglycemia after resection of pheochromocytoma: a case report]

We report a case of severe hypoglycemia following resection of pheochromocytoma. A 39-year-old male was admitted to our hospital with a chief complaint of palpitation. Blood pressure and fasting blood glucose were within the normal range. Computed tomography and magnetic resonance imaging revealed a right adrenal tumor (7.5 x 5 x 7 cm) and 131I-MIBG scintigraphy showed marked tumor uptake of isotope. As plasma and urinary catecholamine levels were very high, a clinical diagnosis of pheochromocytoma was established. Doxazosin and propranolol were administered for 43 days prior to adrenalectomy. During intensive care monitoring 2 hours postoperatively, the patient became drowsy and began to sweat. Although blood pressure remained stable, severe hypoglycemia (38 mg/dl) and hyperinsulinism (63.67 microU/ml) were confirmed. Infusion of 50% glucose improved these symptoms and plasma glucose level and insulin secretion normalized within 15 days of surgery. We also reviewed 25 cases of hypoglycemia after resection of pheochromocytoma. We recommend close monitoring of blood glucose for at least 6 hours after adrenalectomy for pheochromocytoma.