What happened, in summary

A 44-year-old woman had a history of triple-negative invasive ductal carcinoma in the upper outer quadrant of her left breast. The original tumor was classified T2N1. She underwent a modified radical mastectomy with immediate reconstruction. Final pathology showed a 2.8 cm invasive ductal carcinoma with one of 15 lymph nodes involved.

After surgery, she received dose-dense doxorubicin and cyclophosphamide, followed by paclitaxel. She then remained free of a local recurrence for five years.

Five years later, she discovered a new mass beneath a supernumerary nipple at the inframammary fold. The new lesion had a different histology and receptor profile and was considered a separate primary cancer arising in accessory breast tissue rather than a recurrence of the original invasive ductal carcinoma. This distinction separated the first tumor’s triple-negative status, nodal involvement, mastectomy, and chemotherapy from the later tumor’s hormone-receptor expression and different treatment pathway. After treatment of both cancers, she was described as currently having no evidence of disease.