what kind of lumps don't show up on mammogram?

I am 37 years old and I found a new lump about 3 weeks ago.  My period came and went and the lump remained, so I went to my doctor.  She said she wasn't concerned with how it felt, but just to placate me, she'd order a ultrasound.

For the record, my last mammogram and ultrasound was 5 months ago, due to another lump which turned out to be scar tissue from breast implants. However, neither one of those tests detected that lump, or even another lump that has been in the breast for 14 years.  I really don't have any faith in mammograms or ultrasounds.  I am told that I have dense breast tissue.

3 months ago I had the old implants replaced with new implants, and the scar tissues lump taken out and biopsied.  It was indeed just scar tissue.

At the time I got the new implants, I was told that I could not have another mammogram for 6 months, in order to let me new implants heal.

So, back to the current lump:  Yesterday I had the ultrasound.  It could not detect the lump at all.  The sonogram tech was so nice and showed me the screen, telling me that she could not see a lump of any sort.

She showed the films to the radiologist, and he was also not alarmed, since nothing showed up.  He said to watch it and if it's still there in a few months time, have a mammogram.

My doctor can feel the lump and so did the sonogram tech, so I'm not crazy or making this up.  So, how can everyone feel a lump (it's small, near top of the breast, almost in the armpit area), but yet NOTHING shows up on the ultrasound?

Just wondering where I should go with this.  I really don't want to do additional surgery at this time, since I just had the breast augmentation 3 months ago.  My doctor is recommending the 'watch and wait approach'.  How does one 'watch and wait' without letting the anxiety drive you crazy?

Thanks!

[PaulMD]

Hi there.

I understand your concern regarding this.  Your lump maybe really be due to scar formation or other benign conditions like fibrocystic disease the usually won't show up on mammogram or ultrasound.  With no intention to scare, a type of breast cancer may also look benign on mammogram which is called Lobular breast cancer.  A more definitive procedure that can tell us what is causing the lump is to have it biopsied, whether through fine needle of through core biopsy.  You may also want to ask your doctor about breast MRI as this would give you a clearer picture (though the implants may cause difficulty in interpretation) I suggest you discuss these options with your doctor.  Regards and God bless.