I'm 43 years old and was recently told I have dense breasts, which led me to get an ultrasound where they found a mass that was undetected on the mammogram, they said it was "probably benign" and "probably a fibroadenoma." I'm concerned that they are mistaking a phyllodes tumor for a fibroadenoma, as I know the former is more common in women over 40 and the latter, in women in their 20's and 30's. In the course of all this, I got my records and found that my breasts are becoming increasingly dense instead of less dense (from not dense, to scattered density, to heterogeneously dense in three years) as one would expect. Is this something I should be concerned about? Also, the radiologists opinion was to wait for 6 months to see if the mass grows or not, but I'm very skeptical of this as well. I do not know my family history, as I am adopted, so this concerns me as well.