末期腎不全患者に合併したアルドステロン産生副腎腫瘍の1例

Abstract

A 53-year-old female had a history of long-term hemodialysis. Periodic follow-up abdominal ultrasonography revealed a tumor measuring 4 cm in diameter in an area adjacent to the upper pole of the right kidney. Abdominal computed tomography and magnetic resonance imaging confirmed a right adrenal tumor. Furthermore, adrenal scintigraphy after dexamethasone inhibition showed accumulation in the right adrenal gland. An endocrinological test revealed that the plasma renin activity (PRA) was normal, and that the plasma aldosterone (PAC) level was increased to 1, 021.8 ng/dl. The PAC-to-PRA ratio (ARR) was 5, 109. Under a diagnosis of aldosterone-producing adrenal tumor, laparoscopic right adrenalectomy was performed. After surgery, the PAC level was normalized. Pathological findings showed adrenal cortical adenoma. Primary aldosteronism causes hypertension, hypopotassiumemia, hyporeninemia, and hyperaldosteronemia via excessive secretion of aldosterone in the adrenal glands. However, the patient showed a high serum level of potassium due to anuria, and hypertension was not noted. Thus, some dialysis patients with primary aldosteronism do not show any typical clinical symptoms. A previous study also indicated the presence of hyperaldosteronemia in patients with end-stage renal disease. A diagnosis should be carefully made.