Abstract
Hypertension and norepinephrine hypersecretion in a 59-year-old woman suffering from malignant pheochromocytoma with multiple metastases were appropriately controlled with α- and β- blockers, and α-methyltyrosine (α-MT), a catecholamine-synthesis inhibitor. Metastasized vertebrae were treated with external radiation to relieve pain, but this treatment had to be interrupted at a total dose of 20Gy because the patient suffered acutely exacerbated hypertension (200/110mmHg), tachycardia (160beats/min) and a low-grade fever. Simultaneously her serum levels of LDH, potassium, urea nitrogen, creatinine, white blood cell count, CRP and norepinephrine were significantly increased, suggesting that this episode was due to radiation-induced tissue destruction and the leakage of catecholamines and possibly interleukin-6, a cytokine mediating inflammation which is reportedly present in pheochromocytoma. The marked hypertension was controlled by continuous iv administration of phentolamine and propranolol. Athough radiation therapy effectively relieves pain due to neoplasmic metastasis to the bone, physicians should be aware that life-threatening complications such as the above occur in malignant pheochromocytoma. Sufficient pretreatment with adrenergic blocking agents and/or α-MT and careful monitoring of the patient's general condition during radiation therapy, even at a low dose, are highly recommended.
