| Abstract: | The evaluation of computed tomography (CT) for detecting aldosterone-producing adenoma in primary aldosteronism was performed by comparison with adrenal scintiscan; determination of aldosterone in adrenal or renal veins, retroperitoneal pneumography and adrenal venography was reliable for diagnosis of adrenal tumors in pheochromocytoma or Cushing's syndrome, but not so effective for small adenoma of primary aldosteronism. An abdominal CT scan was performed on six patients with primary aldosteronism, one with idiopathic hyperaldosteronism and one with glucocorticoid responsive hyperaldosteronism; in an attempt to evaluate the utility of this noninvasive procedure. Diagnosis of hyperaldosteronism was made by demonstrating the elevated plasma aldosterone concentration and aldosterone secretion rate, normal excretion rate of urinary 17-OHCS and 17-KS, and low plasma renin activity. The CT scan correctly predicted unilateral adrenal adenoma in all the patients with primary aldosteronism of which the findings were identical to those demonstrated by surgery. The diameter of these tumors ranged from 10 X 7 X 6 to 19 X 17 X 14 mm. Also the CT scan in idiopathic hyperaldosteronism and glucocorticoid responsive hyperaldosteronism showed bilateral adrenal hyperplasia and bilateral normal adrenal glands, respectively. The pathological findings in these two cases disclosed the adrenal hyperplasia of zona glomerulosa and adrenal hyperplasia of zona subglomerulosa accompanied by a normal thickness of the adrenal gland, respectively. The precision of the CT scan, adrenal scintigraphy and determination of plasma aldosterone in the adrenal or renal veins were almost equal to the diagnosis of the localization of adrenal adenoma. It is concluded that the CT scan is a noninvasive and most useful method for the localization of aldosterone-producing adenoma and helpful in distinguishing adrenal adenoma from adrenal hyperplasia. |
