Renin-Secreting Renal Neoplasm and Hypertension with Hypokalemia

Antihypertensive medication was ineffective in a young woman with severe, progressive hypertension of 6 years' duration. Serial excretory urography, catecholamine excretion, aldosterone excretion, and serum potassium levels were normal until hypokalemia was noted. Further evaluation showed a renal neoplasm and elevated plasma renin activity and aldosterone excretion. Renovascular embarrassment was not found by radioactive hippuran or impedance renography. Nephrectomy promptly initiated a dramatic fall in the blood pressure and in plasma renin activity. The tumor was characterized morphologically as a hemangiopericytoma that contained high concentrations of renin activity and Bowie-positive granules. Postoperatively, the patient has been normotensive and normokalemic without medication. Renin activity in the peripheral plasma is normal.