Small mediastinal Lymph Notes

I recently participated in a Calcium Scoring screening through a local hospital.  In the Incidental Findings they indicate I have "numerous, small mediastinal lymph nodes, the largest in the pre-carinal region of 1.6 cm in diameter."  I am not sure if this is something I should be concerned about or pursue further.  I am a 56 year old female, not overweight, excercise regularly, NEVER smoked, NEVER chewed tobacco, and do not drink alcohol in excess.  I have never had any health problems to date.  Any comments or ideas?  Thank you.