I got gyno from doing a M-LMG cycle. Only in my right nipple though. I went to doctor and they diagnosed it and gave me Tamoxifen for it. I still have it and I am going to go back to doctor in about 3 months for it, if they can't offer me anything else chemical wise to try to take care of it then they will do surgery to cut it out. I don't have the lump under the nipple anymore but I just have what appears like a juicy fatty soft layer under my nipple that just makes my nipple point out weird and fatty like. I am at around 18% BF right now but I still had it when I was around 12%. You can ride it out and do some cycles then go to doctor, or if it is a big deal to you then I would go to the doctor straight away because they might be able to stop it.