is a hard lump dangerous

I am 36.I had a bone marrow transplant in 1997 for lymphoblastic lymphoma.My mother had breast cancer and also 2 aunts on my fathers side.I was on premarin and provera post transplant for 41/2 years I also take immuran for graft vs host disease.I have a hard unmoveable lump on my r breast.i have had a previous biopsy on my l breast which was fibrocystic but that lump was totally different it was smooth.I have large dense breasts and I'm scared it wont show up on a mammogram.I have a doctor's appt tues with my G.P.and I am scared to death please give me an honest opinion soonThanks susan

[CCF-RN,MSN-rf]

Dear Susan:  A hard lump should be examined.  It is impossible to know what it is without further investigation.  A mammogram is an appropriate first step.  Sometimes an ultrasound or MRI can further clarify situations.  If the lump can be felt and the doctor is concerned, a biopsy can be done even if the mammogram is negative.

[surgeon]

a hard unmoveable lump is of concern. No matter what the mammogram shows, a new lump needs either some form of biopsy or very careful watching. It's not possible to make much of a guess without being able to examine it; but a newly discovered lump which is hard and unmoveable ought to have a biopsy, in my opinion.

[wickie]

Thank you for responding so quickly I guess I should tell my G.P. to send me to a surgeon regardless of my mammogram which by the way is booked for the end of August as a routine yearly exam