Rapidly progressive giant renin secreting tumor: a rare case report.

Eleven years ago, a 25-year-old female patient developed hypertension. Eight years ago, her BP worsened and tests showed hypokalemia and elevated 24-h urinary potassium. Enhanced CT revealed a left renal upper pole nodule. Three months ago, enhanced MRI and CTU showed a huge left retroperitoneal cystic-solid mass. Endocrine tests revealed significantly elevated supine/upright renin activity and angiotensin II concentrations, slightly elevated aldosterone, and serum potassium value of 3.5 mmol/L. She underwent open radical left nephrectomy and postoperative pathological examination confirmed the diagnosis of juxtaglomerular cell tumor. The endocrine tests and blood pressure turned completely normal 2 weeks after surgery.