Extra-adrenal pheochromocytoma

A patient with a functioning pheochromocytoma arising in the organ of Zuckerkandl is described. The catecholamines and their metabolites were measured serially in pre- and postoperative urine samples and in the tumor itself using an improved technic. Electron microscopy of the tumor showed abnormal giant mitochondria in addition to previously described catecholamine granules. The content of cytoplasmic and mitochondrial enzymes of the tumor was compared to that of normal adrenal medulla; the results suggest that the increase in mitochondrial size is not accompanied by a substantial increase in enzymatic activity.