My daughter is 14. her right breast is a smaller and also hard,then she has a painful lump under her right armpit why?

Exam needed: Have her examined by a pediatrician, physician, gynecologist or surgeon. The painful lump in the axilla could be an abscess or a rapidly enlarging lymph node. The difference in breast size may not be significant,but the difference in consistency of the right breast raises concern even though breast cancer in a 14 year old girl would be extremely rare.