Lessons from a Delayed Diagnosis of Reninoma: A Surgically Curable Cause of Resistant Hypertension

Juxtaglomerular cell tumor (reninoma) is a rare renin-secreting renal neoplasm and a surgically curable cause of secondary hypertension. Diagnosis is frequently delayed because of nonspecific manifestations and the absence of significant hypokalemia in some patients. We report a 27-year-old woman with a 6-year history of resistant hypertension associated with recurrent syncope and New York Heart Association class III exertional dyspnea. Laboratory evaluation revealed borderline hypokalemia (3.6 mEq/L), markedly elevated plasma renin (530.1 mIU/L) and aldosterone (1388 pmol/L), and a low aldosterone-to-renin ratio (2.61), supporting renin-mediated secondary hyperaldosteronism. Multiphasic computed tomography angiography demonstrated a 28 × 25 × 34 mm left renal cortical mass with progressive delayed enhancement and late homogeneous filling. Percutaneous biopsy supported the diagnosis of juxtaglomerular cell tumor. The patient subsequently underwent partial nephrectomy, with conversion from a laparoscopic to an open approach because of intraoperative insufflation failure. Histopathological examination confirmed the diagnosis. Six weeks after surgery, blood pressure normalized without antihypertensive medication, while plasma renin, aldosterone, and serum potassium returned to normal. This case highlights the diagnostic value of marked hyperreninemia, a low aldosterone-to-renin ratio, and progressive delayed enhancement of a renal cortical lesion in young patients with resistant hypertension. Early recognition may facilitate nephron-sparing surgery and prevent prolonged cardiovascular complications of uncontrolled hypertension.