child breast abnormality

i have a one year old daughter whom i observe that her left breast is much bigger than her right breast. when i touched it i feel theres a small mass inside. is it normal for a one year old to have a breast like that? i will appreciate for your immediate concern regarding this problem. thank you

[grlsmom3]

My 19 month old daughter has the same thing. She has one breast larger with lump. It seems to be going down with each passing month. I think it is just left over hormones in her system from me nursing her. That is the idea I got from the doctor when she was smaller. She said it is called witch's milk and it is strictly hormonal and is would resolve on it's own and she seems to be right. I would contact the doctor although if  it doesn't seem to improve over the next several months.