Yes core biopsy after mammogram and ultrasound - DCIS identified an due to breast density my surgeon said best tongsve MRI to ensure no surprises - surprise was it wa much larger and hence change from lympectomy to mastectomy - biopsy is only a tiny slice so they never know until after surgery what's in there. But thankfully mine came back as all DCIS. It's a journey from biopsy results to post surgery results it was 7 weeks.