Hey.. I m a girl aged 17, 85kgs (:( overweight ), approximately 165-175cm tall, no previous breast cancer or other diseases in my immediate family (that i know of) and i ve found a lump underneath my armpit.. It s not sore most of the time, only occassionally and sometimes if i use roll-on deoderant.. I don t know what it is or what it could mean.. Could you help?? Thanks...