Hi,
The finding of a nodular density on your mammogram, refers to fibrocystic changes which is usually a benign condition that occurs in at least 60 percent of all women of child-bearing age.It is not a risk factor for breast cancer.
With Fibrocystic changes,your breasts may feel tender,swollen and full with a dull pain.They may be sensitive to touch with a burning sensation.This discomfort is normal and does not indicate the presence of disease.
The problem with Nodular density is that it can make the mammogram more difficult for radiologist to interpret. For this reason, your doctor has requested a breast ultrasound to make sure that there is nothing there to be concerned about.
Take care and best wishes...