Ultrasound and Mammogram

HI,
I am new here and have a question about what an ultrasound can see vs a mammogram.  My doctor found a lump in my left breast about a month ago.  I had a diagnostic mammogram of both breasts as I have just turned 40.  I received a call from the clinic asking me to come in for a 2nd mammogram but not on the left breast (where the lump was) on my right breast.  The additional films revealed a "roundish" mass and an ultrasound was ordered.  I had the ultrasound today and the technician could not find the mass? She has asked me to come back in six months for a follow up mammogram.  Should I be concerned?  Why would an ultrasound not see a mass? I am pretty scared and not sure I can handle six months of worry.  She showed me the mammogram and the mass was definately there?

thanks,
Shannon

[japdip]

Mammograms & Ultrasounds often "see" different things as they are entirely different tests. The Technician is NOT the person to advise you when to return or for what type of examination; this is something that your prescribing Physician would be responsible for after receiving the final reports on all the films. I would advise you to discuss this in detail with him/her as to what type of test you should have as a follow-up and when to have it done. As a rule a Radiology report on both Mammogram and Ultrasound will contain a BIRADS score (0 to5) and this will indicate what follow-up is required. Contact your Physician for a detailed explanation of all 3 reports and you can request a copy for yourself also. Regards ...