Hi Bluegirl27, I'm so sorry you've had a recurrence. From what I can interpret, you had an ultra-sound guided biopsy May 10 (I'm guessing this was where the IDC diagnosis came from). The 6/13 MRI "saw" the mass that was biopsied (they know it was the same mass based on the metal clip left behind during the biopsy), and also identified a separate mass of 0.8x0.5 cm in the same breast. "Inferolateral" means the second mass was below (towards your feet) and to the side (farther away from the breastbone) compared to the mass that was already biopsied.

Unfortunately, the MRI can't tell you whether that second mass is also cancer, or is a benign finding. Your doctor may recommend getting a biopsy of the second mass, especially if you are talking about a lumpectomy instead of mastectomy.

Good news is that the lymph nodes look fine on MRI, and nothing suspicious in the right breast!

Whether it's possible to have a second tumor with different characteristics.... I don't know for sure. I think it would be unlikely that the second tumor (IF it does turn out to be a tumor - and yes, enhanced is suspicious but still not a guarantee) would be Her2+, for example, but very little is flat out impossible given the variability of the body. I suppose it is theoretically possible to have both a recurrence and a new primary at the same time, which could be completely different from each other in terms of Her2 or ER/PR. I have it in my head that the odds of that situation are much smaller than this being two sites of recurrence that are genetically linked, but I'm not sure that assumption is based in fact. A great question for your Dr, for sure. I wouldn't be at all surprised if there was some minor variation, like the Ki67 being 10% instead of 20%, or ER being 75% vs. 85%. But if your next step is a mastectomy, you can be sure that the pathologist will measure those characteristics from both sites, so you'll have that information before the subsequent phase in your treatment plan.