Don't feel like you are alone in asking this question, because it is relatively common. Mammography (breast X-ray) is when low-dose/amplitude x-rays are used as a screening exam to examine human breast tissue. I am assuming that you don't have much experience with x-rays (or reading x-rays), but when looking at an X-ray some structures show up as darker than others, and some are lighter depending on the density of the object. Typically very dense objects like bone show-up bright white. Radiologist
reading mammograms take advantage of this effect since most cancers are slightly more dense than the surrounding tissue, making it possible to pick up abnormalities.
Also some cancers have something called microcalcifications (small calcium crystals...like bone) that show up as small specks of bright white. The abnormal findings on a mammogram can be quite subtle however, because every breast is different, and some people have relatively dense breast tissue to begin with, so a cancer might not show up as easily. Also a very small tumor may not show up on the X-ray. Furthermore, if the cancer isn't a different density than the surrounding tissue, then it won't look different at all. That is why currently it is recommended to perform regular self exams, in conjunction with a mammogram +/- an annual exam by a physician.
The hope is that you will be able to pick up something on exam that wasn't picked up by the mammogram. I hope that this answers your question. If you have any specific questions about your own history or exam, I would recommend a consultation with your local breast surgeon
, or primary care physician
. Best of luck.