Extra-adrenal pheochromocytoma manifesting renovascular hypertension.

A case with extra-adrenal pheochromocytoma, which was found by chance in the course of renovascular hypertension, is reported. The tumor was on the stenotic portion of the right renal artery. The results of examinations for pheochromocytoma were not conclusive, that is, inconsistent elevation of plasma catecholamines and urinary catecholamine excretion, equivocal results of pharmacological tests for pheochromocytoma, and negative results in [131I]metaiodobenzylguanidine scintigraphy. The stenosis of the right renal artery disappeared, the blood pressure was normalized by surgical resection of the tumor, and the extra-adrenal pheochromocytoma was finally diagnosed by pathohistological findings. Renovascular hypertension appeared to be the primary cause of this hypertension, judging from the significant decrease in blood pressure induced by an angiotensin II analog and a renal vein renin ratio of 7.3. Even in the case of obvious renovascular hypertension, the possibility of this unusual coexistence with pheochromocytoma should be considered.