Hematoma or Worse?

I have an eleven year old daughter who has a lump in her breast.  She noticed the lump the day after she had fallen and hit her breast on the floor.  The lump was very hard, large, and sore to touch, and her breast was a light red color in that particular area.  We have been putting ice on it and the lump has really gone down in size, not as hard, and the redness and pain went away, but then I checked her today and it seems to be bit bigger again.  If she did hurt it from the fall how long does it take to go away?  And should I be concerned that it may be more than an injury?

[CCF-RN,MSN-rf]

Dear tangles:  It can take quite a while for a hematoma to resolve.  It is highly unlikely to be anything related to cancer, especially since her breasts are probably not yet well developed.  Since you can relate this to a recent injury, it is reasonable to give it some time to heal.  However, if this persists and you are worried, you could have it checked out by her pediatrician.