16 month old granddaughter has dime size lump in the middle of her
chest. I think it is her sternum. She has had it since she was a month old,
I am the grandmother and never have seen it before, I have her every few week, given her baths. I thought it was a button under her shirt.
My daughter said, she asked the doctor, and she said there was nothing
to worry about. I just found this out. You can not see this lump unless
she holds her shoulders back. What could this be?

Please help me.