You're quoting a report about your ultrasound and asked "Anyone know what it means?" If the report starts with "Probably benign mass," well, "benign" means not cancer. What it means is that you have a mass in your breast tissue that is probably not cancer. Waiting a week for a mammogram after this report is pretty rough. Call your doctor's office and talk to his or her nurse and say you would like to know more about what the report is saying, and don't want to wait not knowing anything. They shouldn't leave you hanging.