Liver biopsy post normal petscan?

I have stage 2 breast cancer (1.8 in breast and 1.2 in one lymph node). Bone scan normal, CT with contrast showed multiple lesions on liver, so had petscan and that came back notified liver but was told Oncologist might still want liver biopsy. I’m thinking overkill? Liver biopsies are difficult and don’t want to stir up an area that doesn't need stirring. Anyone here ever have clean petscan but then get abnormal results from liver biopsy?