Clinical value of plasma renin activity and aldosterone concentration in the evaluation of secondary hypertension, a case of reninoma

[A rare cause of hypertension with hypokalemia: A case of reninoma]

Reninoma or juxtaglomerular cell tumor is a rare usually benign renal renin secreting tumor. We report the case of an 18-year old woman, without any medical history, investigated in our hospital's emergency department for a bilateral papilledema. Ambulatory ophthalmological investigations were performed because of a newly occurring blurry vision, associated with diffuse headaches. Cerebral mRI and lumbar puncture recommended by the ophthalmologist and neurologist excluded intra-cranial hypertension. The patient presented with severe hypertension. Laboratory values showed hypokalemia, compensated metabolic alkalosis and microalbuminuria. During the hospital stay, she developed AKIN 1 acute renal injury. Ultrasound revealed a tissular cystic lesion of the superior pole of the right kidney. Abdominal mRI confirmed the lesion and raised suspicion for a renal cell carcinoma without calicial or vascular invasion. Plasma renin value was >500 mUI/L with normal values for plasma aldosterone. Renal biopsy diagnosed a juxtaglomerular cell tumor. After an aggressive initial treatment, hypertension remained well controlled with spironolactone only, finally allowing for withdrawal of all antihypertensive medications. Robot-assisted laparoscopic partial nephrectomy was performed. Studies of the operative specimen confirmed the diagnosis of benign reninoma. Clinical follow-up showed complete resolution of clinical and biological parameters.