IDC and DCIS?

Most IDC starts as DCIS, so it's very common to find IDC and DCIS together.

DCIS is when the abnormal cells are confined to the duct milks. It is a non-invasive condition. If the DCIS cells continue to evolve, at some point they may undergo a biological change that gives the cell the ability to break through the wall of the milk duct. This change turns the cell into an invasive cancer and at this point the cell moves into the open breast tissue (outside of the duct) and develops from there as IDC - it is no longer DCIS.

Usually when this progress happens, some of the original cells progress but others don't, so some cells remain in the duct as DCIS while other cells have become IDC and are in the breast tissue. This is why IDC is often found with some associated DCIS.

This graphic is from the breastcancer.org information pages. At the bottom you can see a cell with DCIS in the middle of the duct and IDC on the outside of the duct in the breast tissue.

Mine was thought to be DCIS but after all was said and done it was invasive and I ended up with a mastectomy.

Kate8, in my case, I did have two separate areas. One was found to be DCIS, and the other one was like Beesie said, IDC with DCIS. There was actually more DCIS than IDC, but the IDC was considered the primary diagnosis because it is a higher stage. I was afraid that having two areas in the same breast would automatically mean a mastectomy for me, but they were small enough and close enough together, and I was fortunate to have a very experienced and skilled surgeon who was able to treat them as though they were one larger area rather than two separate ones. My choice was a lumpectomy. I had to have a re-excision because my margins did not come back clean the first time. It was the DCIS that remained, and my surgeon successfully obtained clean margins the second time.

This does not mean that you will also have two areas of cancer. It's possible that neither area will be positive or that only one is. I did also have a mass that showed on my ultrasound, but it was benign. Hoping your results are negative for any cancer, but if not, you may still have options for your surgery even with two suspicious areas, especially if it is early-stage. Hang in there; I found the time before the biopsy and the time waiting for those results to be the worst part.

Yeah, my DCIS was all around my IDC - I didn't even learn about it until after surgery. I listed it on my profile here without really thinking about it. Now I'm wondering if I should remove it. I didn't think about how it could be misleading.