Hypertension, Polydipsia, Polyuria, and Hypokalemia Associated with Renin-Secreting Wilms' Tumor in a Child

ABSTRACT

A 3-year-old boy with Wilms' tumor had unusual severe hypertension, polydipsia, polyuria, and hypokalemia. Physical examination on admission was unremarkable except for the presence of a smooth, firm mass in the right abdomen. Computerized tomography showed a tumor occupying upper two thirds of the right kidney. Plasma renin activity and aldosterone concentration were markedly elevated, 37.7 mg/ml/hour (normal supine 0.15-2.33 mg/ml/hour) and 120.1 ng/dl (normal supine 1 to 16 ng/dl), respectively. His hypertension, varied from 150/90 mmHg as high as 240/180 mmHg, was not effectively controlled by antihyperensive drugs. Because of concern for the complications of hypertension, a right nephrectomy was performed on the sixth hospital day. At laparotomy, there was no evidence of mechanical compression of the renal artery by the tumor. The tumor, about 8 cm in diameter, was confined within the renal capsule without involvement of the renal blood vessels at the hilum. Histopathologically, it was characteristic Wilms' tumor of favorable histology. On electron microscopy, the tumor cells contained many electron dense secreting granules in the cytoplasm, suggesting that the tumor itself was the source of the renin and cause the clinical manifestations. Shortly after nephrectomy, signs and symptoms were relieved dramatically, and plasma renin activity and aldosterone concentration were also decreased to normal.