18 Years old, Hard tender mass behind nipples

[Lewisrowezer]

Hey all. The past few months/year I've came to notice a hard mass behind both of my nipples which didn't used to be tender to touch but is now quite tender to touch/squeeze, more so the left nipple but also a little on the right. 
I didn't really think anything of it however ever since I have been weightlifting in the gym I heard of gynecomastia as something people who are on steroids get. Obviously I am not on steroids which is why there is a lot of room for concern for me. 
I have recently also heard a lot of things about breast cancer in males, etc and have heard that a hard lump behind one or both nipples could be cancer..I have a doctors appointment in a few weeks but feel like I need to talk about this with someone now, so I felt this forum was a good idea. I have submitted two pictures of the current state/look, any advice or reassurance would be very much appreciated. Thank you!

[George Pope, M.D.]

It is possible you have a small amount of breast tissue behind each nipple. This can present itself as "puffy nipples" when your nipples are not erect or cold, or it can cause tenderness from time to time.  It's good you are seeing a physician about this, but it's most likely nothing serious.
If it progresses, or if you have a puffy nipple appearance when not erect, AND if it's bothersome to you, you may want to consider excision.  At your lean body weight, liposuction would not be necessary, and the tissue could most likely be removed under local anesthesia.  See what your physician recommends; he or she should refer you to a plastic surgeon if surgery is required.
Best of luck-
Dr. Pope, MD

[Dr. Elliot Jacobs]

While cancer of the breast is known to affect men, it is extraordinarily rare in younger men.  Further, it would be virtually impossible for it to appear simultaneously in both breasts in a young man.

As Dr. Pope said, you probably have a small amount of breast tissue beneath each nipple -- this may be natural and not related to steroids (whether you have taken them or not).

Sometimes tenderness can occur when guys get uptight about some excess tissue under the nipples -- and then they pinch, squeeze, etc -- and then wonder why there is some tenderness.  Leave 'em alone -- pinching won't make it go away!

Best to get a consultation with a gyne specialist in your area for a complete evaluation.

Dr Jacobs