Medically treated renin-mediated hypertension suspected to be caused by reninoma

Background Reninoma, a renin-secreting tumor, is a rare but curable cause of secondary hypertension, typically treated with surgical resection. However, data on pharmacological management of cases where surgery is not feasible remain limited. Case presentation A 35-year-old man presented with pontine hemorrhage, severe hypertension (252/165 mmHg), hypokalemia, and metabolic alkalosis. Laboratory evaluation revealed a serum creatinine level of 4.6 mg/dL and markedly elevated plasma renin and aldosterone levels. Renin-mediated hypertension due to suspected reninoma was considered after ruling out renal artery stenosis, and lateralized renin secretion was confirmed using renal vein renin sampling. Surgical resection was deferred because of decreased renal function and the uncertain location of the suspected tumor. The patient was treated with an angiotensin II receptor blocker and a low-dose aldosterone antagonist. Blood pressure improved within 1 day, and hypokalemia resolved without potassium supplementation. At the most recent outpatient follow-up, his office blood pressure was 134/78 mmHg while his serum creatinine level remained stable at 2.5 mg/dL. Conclusion For patients with suspected reninoma who are not candidates for surgery, medical therapy targeting the renin–angiotensin–aldosterone system may offer a safe and effective alternative for achieving long-term stability in blood pressure and renal function.