Clinical Diagnosis vs Pathology

Dear all

I signed up to this community a couple of months ago to learn more about breast cancer. My 57 yr old wife was diagnosed by biopsy in December 2019. A short context....In between normal mammograms (late Oct 2019) she felt a lump. In early December she had a biopsy that revealed a grade 1 tumor of the mucinous type. ER+ PR- Her2 Neg (score 0). An ultrasound showed a 2.1 cm spiculated mass, no lymph involvement. Prior to surgery she had an initial consult with her experienced oncologist surgeon who does only breast surgery. He was quite buoyed by the biopsy path and felt very confident of an excellent prognosis. He felt confident that after surgery, she would move to radiation therapy and then hormone therapy

On Jan 13 my wife had her surgery. It went well, 2 sentinel nodes were removed. The surgeon told me that the nodes felt soft and that given the U/S showing no lymph invasion and given that mucinous carcinoma has a 90% chance of no lymph invasion, he felt the results would be good. Today we met with the radiation oncologist. We received the path report. The mass was 4.3 cm. 1 of 2 nodes was positive with a 3mm macro met. There was a 1mm extranodal extension observed

So....the pathology revealed something significantly more sinister than the clinical and biopsy evaluations. How could a seemingly "safe" mucinous tumor be so invasive so fast?

More importantly we are worried about the positive lymph node and also the extranodal activity. Does anyone have any thoughts on how these two findings can impact disease free survival and overall survival?

with many thanks