Elevated plasma renin (66.24 pg/mL; approximately 2.0 times the upper reference limit of 32.8 pg/mL) and urinary normetanephrine (827.02 μg/g Cr; approximately 1.8 times the upper reference limit of 461 μg/g Cr), together with the identification of a hypervascular retroperitoneal mass, supported the suspicion of a paraganglioma. Here, REN is linked to paraganglioma.