newly diagnosed terrified!!!

I'm so sorry you are going through this.  Really, you are (in my experience) at the scariest part--not knowing.  Once you have all the information and a plan in place, most people feel much, much better.

MRi will pick up some things mammogram misses, just like a mammogram will pick up something an MRI misses.  So doing both just gives the doctor a more complete picture of the breast. MRIs are very "sensitive," that is, they pick up a lot, but because they're so "sensitive," they often have what are called "false positives," that is, something showing up that shows up as suspicious but in the end turns out not to be positive for cancer. 

 I had an MRI before my lumpectomy--both breasts-- and it gave me a lot of comfort because nothing else showed up.  But if it had, I and my doctor would have more information and would be able to make a more informed decision.

 As long as you have DCIS (no matter how much or how high grade it is), it will not be in your nodes.  You won't know that for absolute certain that it's all DCIS til you have the lumpectomy and/or mastectomy, but if all the tests up to this point (core biopsy, excisional biopsy, MRI) just show DCIS, then it seems that's likely what you have.  If it's multifocal then the doctor couldn't get all the DCIS out in a lumpectomy, which is why s/he is recommending mastectomy.

 So whew, it's a lot to digest.  The oncologist can probably explain some of this better and will talk to you about tamoxifen.  In the meantime, you should talk to the surgeon and make you understand what your pathology showed and why he's recommending the mastectomy.  Then you might consider talking to another surgeon--just to get a second opinion.  Ditto on the second opinions with the plastic surgeons.  I got lots of second opinions and they all agreed, which gave me a lot of confidence that I was doing the right thing.

Bottom line:  lots and lots of people have DCIS and do really well.  Just look at the DCIS forum and you will see.  There's also a lot of information on the DCIS forum that can you give you a starting point.  Hope this helps.  Let me know how you are doing. 

I completely understand your fear. The waiting & unknown is always the hardest part. You already received great info regarding your questions about MRI/Mammo, so I won't repeat the information. I will tell you I also suffer from chronic neck & back pain. I had a cervical fusion 3 years ago & still face pain on a daily basis. I had a double mastectomy with reconstruction (I opted for expanders/implants) two weeks ago, & although it hasn't exactly been a walk in the park, it definitely hasn't been anything unmanageable. The pain from the actual surgery has been minimal. I did have some problems with the postop drains, but I think it was the material the drains were made of that caused problems with my skin. Things got much better for me once they were removed. Sleeping has been different, but I've learned to place pillows in various places for support & it's working out just fine. If I have trouble sleeping, it's just from my chronic problem of insomnia, not from pain. As for the reconstruction that involves the stomach, a friend of mine went through the DIEP procedure (where they use tissue from the abdomen) & recovered very well, going back to work in 4 weeks after her surgery. It has been 1 1/2 years since her procedure & she is very happy with the results. It does take a little more time to recover from that type of procedure than the implants & is a longer surgery, but there is less time spent getting the expanders filled & you don't have to go through another procedure to have the implants put in. There are more options for reconstruction than there used to be & they all have their negatives & positives. You have time to investigate things & educate yourself, so take a deep breath & take it a day at a time. I agree that Dr. Susan Love's book is a great resource. Just keep in mind that if your definitive diagnosis comes back as DCIS, you have a great prognosis. Blessings to you. I wish you the best. Keep us all posted!