I'm not sure if this belongs here or not, if not could you please me it.

Ok last year my girlfriend found a painless bump on her upper back, so she went to the doctors and was told it was fatty tissue and there is nothing to be concerned about, but the doctor never ran any tests on it, she just looked at it.

Well as of a few days ago that once painless bump is now so painful it hurts when she moves her arm or even if her hair touches it and the pain runs across the top of her back. The earliest doctors appointment she could get was this Friday, does anyone know what this could be? It semi hard and is about an inch round.

Here is a picture of it