Mammogram report and concerns

I have been having yearly mammograms for almost 20 years. My mother was diagnosed with BC when she was a year older than me. Last week I had a mammo and received a call from my doctor stating they needed to do spot compressions and an ultrasound because of a nodule they see. I picked up a copy of the report from the imaging center and it states, "the breast tissue is heterogeneously dense. There is a nodular density seen withing the patients right breast on bothe MLO and CC view. I guess I'm a little concerned because it was seen on both views. Is this cause for concern? I am going tomorrow for the spot compression and ultrasound and I guess I will know more then. Just having a little anxiety.  Thanks, Debbie

[Cleveland Clinic]

Dear Deb9111955:  It is not uncommon for a density to appear on mammogram that will smooth out with spot compression.  A spot compression will focus on the area of concern so that if the dense tissue is complicating the reading, it will be easier to interpret.  It is anxiety producing but additional evaluation is the right approach any time something out of the ordinary is identified.

[Deb9111955]

I had the spot compressions and then an ultrasound. I was told it was deep in the upper part of my breast but that is was benign. how do they know that without a biopsy?