[The observation of bilateral pheochromocytoma after unilateral adrenalectomy : a case report].

We report a case of bilateral pheochromocytoma which was incidentally discovered by ultrasonography at a health check-up. A 46-year-old female was admitted to our hospital for further examination of a right adrenal tumor. Computed tomography and magnetic resonance imaging revealed a right adrenal tumor, 5 cm in size, and a left adrenal tumor, 1.5 cm in size. High serum noradrenaline and urine noradrenaline levels were noted. 131I-MIBG scintigraphy revealed an abnormal accumulation of 131 I in the tumors. Thus, our clinical diagnosis was bilateral pheochromocytoma. Laparoscopic right adrenalectomy was performed. The histopathological examination revealed pheochromocytoma, no capsule injury and no malignancy. We decided to continue watchful waiting of the left adrenal tumor, because the serum and urine levels of catecholamine were within the normal range after the operation. She has been well with no clinical symptoms, no increase in tumor size, and no elevation of catecholamine for 20 months.