breast imaging results

My 18 year old daughter was referred for an ultrasound after the doctor found a "cyst". after feeling a lump herself.
This area was very tender. We made an appointment with a surgeon at this time. I received a call from the doctor saying the ultrasound did not show a fluid filled cyst but was solid.  After conferring with the surgeon she recommended a mammogram suspecting a fibroandenoma. Two month later after much worry we visited  the surgeon who reported that there was no cyst.  The ultra sound stated "homegenous dense fibroglandular tissue.  The cyst was only lumpy dense breast tissue and nothing was seen on the mammogram.  My daughter can
still feel this area and is very uncomfortable.
She was diagnosed with costocondritis several months ago and the doctor feels that this is the source of pain.  However, she was told by the original physician that she had two very separate issues and that there was definitely a cyst present.
My daughter is extremely upset and I am very confused. What do you recommend?second opinion?new tests?

[Cleveland Clinic]

Dear jodyruth:  Breast cancer is extremely rare in 18 year old women.  Further, most breast cancer is not painful.  A cyst, by definition, is a fluid filled structure.  Since the ultrasound confirmed that this “lump” is not fluid-filled, it is not a cyst.  A fibroadenoma is generally fairly distinct on examination and on mammogram as smooth round lumps that can grow quite large and generally resolve on their own.  From what you state, it sounds as though your daughter has dense breast tissue, which is very common in women her age and can swell and become painful, especially during certain times in the menstrual cycle.  This type of tissue generally feels very lumpy – and can feel painful to touch.  Costocondritis is pain that usually occurs in the joints of the 4th, 5th, and 6th, ribs, which are often behind the breast and can sometimes cause pain referred to the breast.  While these two issues may be separate, they also may be related.  If you are concerned, you might consider an appointment with a medical breast specialist – these are often associated with large academic medical centers.