I am thinking back to when I was 8 years old (now 32) when the children at school picked on me for my 'breasts'. I wasn't overweight.
My parents didn't think there was a problem, so your son is lucky to have a great dad that takes his health so seriously. However, you are clearly in a state of panic, dressing your child to hide 'the problem' and calling the doctor (in the UK you would be really reprimanded for calling a doctor out for this reason - it's not urgent or life threatening). Please, please trust me when I say that this response is a little too hysterical. If you son can see that it is such a frightening experience with you dashing around to mask his breasts, calling in the medical profession and thinking years ahead of how this is going to 'ruin' the rest of his life then all it serves to do is validate the problem way beyond what it really is. This is not life threatening and needs to be fully understood before any rash decisions can be made.
I can tell that your love for your son for his mental and physical well-being is of paramount importance. Whatever might be 'wrong' with your son cannot and will not be 'cured' this weekend. What your son needs right now is the father he knows he can trust, as he probably has done for all 8 years of his life.
Firstly stay cool. Real cool. If you make this out to be the worst thing in the world, your son, who looks up to you will also see it that way. Firstly reassure him that he is normal and healthy. Believe me, if your son had goofy teeth, a big or bent nose or ears that stuck out, he would get just as much teasing. Just because gynaecomastia is often akin to physical femininity, people feel more uncomfortable with it - that it's less 'acceptable' by children compared to a big nose. Really? Try telling that to the kid thinking about killing himself because of the teasing he gets about his nose!
Fortunately today, gynaecomastia is recognised as a medical condition by most physicians. Although around 40% of males have some degree of glandular tissue, only around 5% have significant amounts that often cause psychological problems such as depression and low self-esteem.
I am in no position to make any kind of diagnosis or hormonal assessment on your son. If there is some kind of pathological, diet or hormonal issue, your doctor or endocrinologist is best suited to establish what exactly is going on and what, if any treatment is needed.
I would doubt surgery at this age would be indicated because it might be difficult to assess what may or may not happen during puberty.
All I know from my own experience is that my breast issue did not go away and I just dealt with it. I am by no means a mild case as my breast area hangs over to form a slight fold over the abdomen.
I wish I had a dad that understood my situation, but at the time, society and the medical profession would just have ignored it. Consequently I had to suffer all the stigma so many other guys before me have had to endure.
Initially, the best thing you can do for your son is to give him all the support HE needs. Stop panicking and start spending time with your son and other children if you have any in a way that makes them appreciate all that there is to do and learn about life. Between now and resolution of your son's possible gynaecomastia, I would say that getting on with life in a constructive way, helping your son to deal with any teasing. Otherwise he could grow to really hate himself and I am sure that is the last thing you want.
As an adult I am blessed with a fantastic circle of friends who have been incredibly supportive. And whilst I am going for surgery in the new year, I have not allowed my gynaecomastia affect my work or home life.
Male chest reduction WILL NOT add a layer of happiness to my life, it just serves to remove a layer of sadness.
So please, for you both for your son's sake and your own, play it down, take your time on this journey to make absolutely sure that everything you, your son and the medics do is in your son's best interest.
Best wishes.