Reninoma Presenting in Pregnancy

Abstract

23-year-old Caucasian female was diagnosed with hypertension and controlled with an angiotensinconverting enzyme inhibitor and a beta-blocker. Two years later, she developed hypokalemia. She had normal urineandplasmacatecholaminesandmetanephrines,and aldosterone was appropriately suppressed in a saline suppression test. Computed tomography angiogram (CTA) andmagneticresonanceangiographydidnotdetectstructural renal or adrenal causes. She then became pregnant; theangiotensin-convertingenzymeinhibitorwaschanged to a calcium channel blocker and methyldopa, without however maintaining adequate control. At 26 weeks of pregnancy, she underwent cesarean section for hemolysis, elevated liver enzymes, and low platelet count (HELLP syndrome);thenewborninfantdiedaftera4-weekcomplicated course in intensive care. The patient was referred later to the National Institutes of Health for uncontrolled hypertension. Her upright plasma renin activity was 20 ng/mL/h (normal, 4.3), and her aldosterone level was 110 ng/dL (normal,21). CTA, magnetic resonance angiography, positron emission tomography, and renal venous sampling established the diagnosis of a 1-cm left kidney renin-secreting lesion (Figure 1, A–C and E). Her blood pressure normalized immediately after a left partial nephrectomy. Histopathology was consistent with a juxtaglomerular cell tu