Catecholamines in the Localization of Pheochromocytoma

Data on urinary catecholamines in a collected series of 75 cases of pheochromocytoma, including 18 of our own cases, indicate that the differential assay of urinary norepinephrine and epinephrine may be of value in predicting the location of the tumor preoperatively. If there is a significant elevation of urinary epinephrine (42 per cent of all cases), the tumor may be expected to lie in or adjacent to one of the adrenal glands in about 95 per cent of cases. Other tumors of this type have been found only in the organs of Zuckerkandl. If the urine contains norepinephrine alone (58 per cent of all cases), the tumor will be found in one of the adrenal areas in about two thirds of the cases and in an extra-adrenal location in the remainder. In a few patients (6 per cent) of this type, the tumor may be extra-abdominal. In some unusual cases more precise information on the location of the tumor must be obtained preoperatively. The demonstration of a marked step-up in plasma catecholamine concentration at the level of the tumor, the sampling being done by venous catheterization, is a useful and safe means of localizing the tumor. Five cases are presented illustrating the use of this procedure.