My Son Who Is 22 Is Bleeding From Both Nipples.

My son who is 22 is bleeding from both nipples. After 2 MRI's, mamogram, and ultra sound they are not finding nothing. His testosterone levels were low a couple of weeks ago, but have since returned to normal.
We are seeing a surgeon next, and why I am not sure. His doctor is recommending an Endrocronologist
but more and more I am wondering if it has steroid use, which he is denying.
What are your thoughts? Can you offer any suggestions. Frustrated here!