抄録
Twenty-seven cases of pheochromocytoma, consisting of 17 patients with sustained hypertension and 10 with paroxysmal hypertension, were studied. The patients, 17 males and 10 females, ranged in age from 10 to 48 years with the mean of 30. 1 years. Abnormal laboratory findings including proteinuria, glycosuria, increased blood sugar, high serum cholesterol, elevated basal metabolic rate and severe retinal changes were found in these cases, particularly in the sustained type. Regitine and histamine test constituted a valuable screening procedure, but tyramine test gave false-negative results more frequently in the paroxysmal type. One spot test1) was positive in 22 of the 27 cases (TABLE I). The tumors consisted of 18 unilateral, of which 11 in the right and 7 in the left, and 6 bilateral and 3 extra-adrenal ones. Four of the 6 bilateral cases were siblings from two different families and 5 had medullary carcinoma of the thyroid. One patient with the biggest bilateral adrenal tumors died preoperatively from cardiac arrest and 3 died from peripheral shock shortly after removal of the tumor. Remaining 23 cases were cured completely.
Abnormally high excretion of catecholamines and their metabolites was found in all of the 27 cases. There was no direct relationship between 24 hour catecholamine excretion and the tumor size (Fig. 1). Most patients with paroxysmal hypertension excreted less than 500 μ g per day of catecholamine, while the patients with sustained hypertension had catecholamine excretion in excess of 500μ g. Like Crout et al. 2, 3), excretion pattern of catecholamines and their metabolites in these patients could be classified into two categories: catecholamine-dominant and metabolite-dominant types (Fig. 2). However, most patients with the catecholamine-dominant pattern had sustained hypertension. The metabolite-dominant pattern was found in almost all the patients with paroxysmal hypertension. Noradrenaline infusion study showedthat the catecholamine-dominant pattern was observed in urine collected during infusion and the metabolite-dominant pattern was found in urine voided 2 to 4 hours after the infusion4). Linear relationship between catecholamine and metabolite excretion was demonstrated in the patients with paroxysmal hypertension. However, the sustained type of pheochromocytoma showed a lower metabolite/catecholamine ratio than the paroxysmal type (Fig. 3). These results suggested that there was the maximal up-take and metabolism of catecholamine in the sustained type. Overflow of catecholamine could be the cause for producing the catecholamine-dominant pattern. On the other hand, tissue up-take in the patients with paroxysmal hypertension might not be fully saturated with catecholamine, and metabolism in the peripheral tissues might be active enough. Thus the latter patients showed the metabolite-dominant excretion pattern.
Based on determination of catecholamine in tumor and urine, Crout et al.3) postulated that a pheochromocytoma of a large size had a slower rate of catecholamine release than a small tumor and escaped detection until the tumor has become large enough. In our study, however, urinary catecholamine excretion and severity in clinical manifestations were not related to the tumor size. We also found that catecholamine content in large tumors differed considerably from portion to portion since they had multiple areas of hemorrhage, necrosis and cysts5). Degenerative changes may reduce the number of tumor cells and catecholamine synthesis, but remaining tumor cell continued to grow. If a small tumor repeated these processes in escaping detection, it would become large and necrotic. We found that patients with large tumors had a more prolonged clinical course (Fig. 4), and all tumors, either small or large, were detected when catecholamine excretion reached certain levels.
