Treatment of metastatic pheochromocytoma with streptozocin

A 58-year-old man who had a malignant pheochromocytoma with hepatic metastasis was treated with 2 g/mo of intravenous streptozocin for 18 months. There was a reduction in his urinary excretion of dopamine (from 33,840 to 731 micrograms/24 hr), homovanillic acid (from 48 to 8 mg/24 hr), and vanillylmandelic acid (from 350 to 74 mg/24 hr). There also was a reduction in the size of his hepatic metastasis (50%) and a right adrenal mass (25%), as well as a marked clinical improvement in his condition. Based on this evidence, I believe further attempts to treat patients with metastatic pheochromocytoma with streptozocin seem warranted.