Selective venous sampling in the diagnosis and localization of phaeochromocytoma.

Plasma noradrenaline levels were measured at several sites in the systemic venous system by selective catheterisation in ten hypertensive patients in whom phaeochromocytoma was suspected on clinical or biochemical grounds. Four patients had localized noradrenaline elevation and the diagnosis of phaeochromocytoma was confirmed at operation. The remaining six patients demonstrated no localized elevation of noradrenaline and there has been no evidence of a tumour on follow up. The technique allows the diagnosis and accurate localization of phaeochromocytoma and is useful in excluding the tumour in patients with essential hypertension.