Talk to Nephrologist on Renal Cell Carcinoma

my mother recently had a ultrasound describing adrenal mass over the upper pile of the right kidney. later on in ct scan it is demonstrated that she has a adrenal mass measuring 6.9 X 4.7 cm covering the mid of the kidney. her right renal vein has also some filling defect. I have contacted the surgeons they are of the opinion that the right kidney should be removed. so please advise whether I should go to a nephrologist or urologist