Painful, hard lumps in both of my husband's breasts- showed on mamogram(mammogram)

A few weeks ago, my husband (36) started having pain in his left breast.  Then a lump formed under the nipple, which became extremely sore & hard to the touch.  The doctor put him on antibiotics, suspecting an infection- this did nothing.  Today he had a mammogram & ultrasound, which showed solid masses in mammary ducts in both breasts- he didn't realize there was a lump in the other breast, it is very slightly sore. They said at first sight it appears to be gynecomastia, but we need to consult w/ our doctor on Friday to discuss next steps.  Is this something we should be concerned about?  We are a little freaked out- did some research, but its a little confusing.  He has put on weight in the past 3 years, which began around the time he started getting cortisone injections in his lower back (car accident in 2001 left him with a titanium ladder and L4 L5 fusion, and constant pain/disc swelling).  He is currently on pain medication, which he is slowly coming off of. Could there be a connection here, regarding the cortisone injections or pain meds?  Could there be other reasons for these growths, and can they be malignant?  Does this sound like something other than gynecomastia?  By the way, he is 6'4" about 240- 3 years ago he was at 200lbs.   Any information would be greatly appreciated!!!  Thank you!