You are doing a comprehensive history and physical on a 20 y…

You are doing a comprehensive history and physical on a 20 year old female.  She tells you that she began her menses at age 12 and her cycles have been regular.  She is not sexually active.  Upon examination of her breast you note that there is a single, well delineated, mobile, small lobular mass in the outer quadrant of the breast that the 10 0’clock position.  This mass likely represents a …