axalary lump

good morning
My daughter is 19 years old and found a lump on her left brest about 8 weekes ago. after an ultrasound they said it should be biopsy they felt it was a enlarged lymph node in the axalry area. after seeing a surgen they sent her for a mamagram and it was enconclusive. they want to do a biopsy know. it has not changed with periods and is movable, does not hurt unless pressed hard on. it appears to be a pea size lump within a swollen lyph node. what could this be at 19 years old.
thankyou mom

[CCF-RN,MSN-rf]

Dear stina:  A lump in a 19 year old could be several things.  Mammography is often not very helpful in young women because of the dense breast tissue.  If the ultrasound suggested a biopsy, then the only way to get to the bottom of this lump is to proceed in that direction.  Unfortunately, when there is not enough information with examination and imaging to help determine the cause of a lump, biopsy may be the only option for finding out what the lump is.