Can a 'solid' mass that needed biopsy be gone in less than a month by itself? Is it possible to go from a Bi-rads 4 to a Bi-rads 0? Here are ultrasound results.

[jess100]

My dr. found a mass during the physical exam on my left breast. I am 31 yo. I did 3 ultrasounds and here are the results.
First ultrasound: at 2-3 o'clock, 2-3 cm from the nipple is a solid lobulated nodule measuring 6x3x6mm in size. Some of the margins are irregular and biopsy is recommended. Bi-rads 4-suspicious.This ultrasound is from sept 17.

I had 2 more ultrasounds after that on Oct 9 and Oct 29. The results are: the area of concern demostrates echogenicity consistent with underlying fibroglandular components without mass. No focal distortion. No abnormal echogenicity. No apparent change from prior studies of Oct 9. If indeed palpable abnormality persist and furthger eval. is warranted, then follow up studies including either MRI and/or breast specific gamma imaging would then be recommended. Bi-rads 0.

I did the first ultrasound in a different facility from the last 2. Where did the 'solid' mass go? Is this possible to get these very different results few weeks appart? What is more recommended to do IMR or gamma imaging? I have my breast specialist app. this thursday. Thank you in advance.

[japdip]

The BIRADS 0 score does not mean that you now have a negative result. It means that further investigation is necessary to assign a definite BIRADS score. I'm not clear as to why the recommended biopsy was not done after the first US rather than having multiple Ultrasounds instead. I would think MRI would be a good choice at this point. The best of course would have been to do the biopsy in Sept as advised.  Regards ...