I had a similar situation. A mass on my left kidney that we surveiled for a couple of years . During that time we watched it grow from 1cm to 2 cm. My son is an interventional radiologist in Portland, OR and he recommended an ablation be done by a classmate of his, Dr. Ryan Kohlbrenner, at UC San Francisco. I had it done about 2 months ago. They froze it to kill it. The procedure had no pain and no recovery time. They covered the entry point with a band aid. The process to get a biopsy and to ablate it were the same so we did both at the same time. I would suggest calling Dr. Kohlbrenner for a referral. Once the mass gets larger than 4 cm it requires more of a surgical procedure. LMK if you have any more questions.