28 A female patient with a rare cause of secondary hypertension: a reninoma
Hussain, I, Verberk-Jonkers, I.A.J.M, Meiracker, A.H van den
Locatie(s): Auditorium 1
Categorie(ën): Parallelsessie
Case: In 2007 a 47-year old obese (BMI 30 kg/m2) female patient was admitted because of dyspnea due to pulmonary congestion, hypertension (219/126 mmHg), and overt hyponatremia (129 mmol/L) and hypokalemia (2.9 mmol/L) with normal renal function without any medication. ECG showed evidence of left ventricular hypertrophy, while echocardiography demonstrated normal LVEF without valvular dysfunction. During admission secondary hypertension was suspected, antihypertensive treatment was started and urinary analyses were ordered. She was discharged with a well regulated blood pressure (140/80) while on five antihypertensive drugs, i.e: furosemide od 40 mg, perindopril 4 mg bd, spironolacton 50 mg od, metoprolol 100 mg od and amlodipine 10 mg od. Unfortunately she was lost to follow-up until readmission in 2012. Again she presented with the same clinical picture of dyspnea due to pulmonary congestion, hypertension (192/91 mmHg), and electrolyte abnormalities (Na 124 mmol/L, K 2.6 mmol/L) while on the same antihypertensive regime as in 2007 with the addition of potassium suppletion. 24 h urinary analysis did show normal levels of cortisol, VMA and metanefrines. Both plasma renin activity (PRA, 150 ng/ml/hr) as well as aldosteron levels (22590 pmol/L) were extremely elevated, indicating secondary hyperaldosteronism as the cause of hypertension. Additional analysis including CT-angio of the abdomen did not show renal artery stenosis, but demonstrated a contrast-enhancing mass of 6x7 cm in the lower pole of the left kidney. Selective renal vein sampling was performed, showing a lateralization ratio of plasma renin to the left of 1.34, indicative of a renin-producing left-sided renal mass. The patient underwent laparoscopic robot-assisted partial nephrectomy. Following surgery there was a reduction in antihypertensive drug requirements (only bumetanide, amlodipine and losartan) while sodium and potassium levels normalized without suppletion due to normalization of both PRA and aldosteron levels (0.4 ng/ml/h and 90 pmol/L respectively). Pathological review showed the presence of a juxta-glomerular cell tumour.
Conclusion: The combination of severe hypertension and hypokalemia is suggestive of the presence of hyperaldosteronism. In primary aldosteronism serum sodium concentration is high, whereas serum sodium concentration tends to be low in secondary aldosteronism, probably due to angiotensin II-mediated vasopressin release. The juxta-glomerular cell tumour , also called reninoma, is a rare cause of secondary hyperaldosteronism with only 80 cases described in literature so far. Our case demonstrates that appropriate analysis and subsequent subtotal nephrectomy can lead to the cure of the disease with remission of hypertension and potassium requirements and normalization of hyponatremia.