Unilateral renal artery stenosis presented with hyponatremic-hypertensive syndrome – case report and literature review

BACKGROUND: Renal artery stenosis is one of the secondary causes of pediatric hypertension. Cases with critical unilateral renal artery stenosis manifesting with the hyponatremic hypertensive syndrome are rare and a comprehensive description of this disorder in the pediatric population is lacking in the literature. CASE PRESENTATION: We describe a 4-year-old boy who presented with severe hypertension, profound hyponatremia, hypokalemia, nephrotic range proteinuria, and polyuria. Distinctly, the diagnosis of hyponatremic hypertensive syndrome secondary to unilateral renal artery stenosis was confirmed in light of laboratory and radiographic findings of severe natriuresis, elevated renin, and unilateral small kidney. Two weeks following nephrectomy, there was resolution of hyponatremia, hypokalemia, nephrotic range proteinuria and hypertension. CONCLUSIONS: Findings of hyponatremia, hypokalemia, hypertension, polyuria, and unilateral renal hypoplasia can be attributed to a unifying pathology of unilateral renal artery stenosis. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12882-019-1246-9) contains supplementary material, which is available to authorized users.