Im a 16 year old boy and I have puffy nipples with lumps underneath. The diameter of them is pretty large too and they protrude out when they're both puffy and hardened. Im really physically fit and workout, so it's not simply fat. I read that this could be a result of an imbalance of elevated estrogen levels, but everything about me indicates otherwise lol (deep voice, lots of hair, easily obtained/retained bulky muscle, etc) Thanks! This can get embarrassing...