What happened, in summary

A 51-year-old woman presented with a left breast mass that had been present for about 2 months. Examination and mammography showed an irregular lesion roughly 4 to 4.5 cm in the upper outer breast, without suspicious axillary lymph nodes.

Core-needle biopsy diagnosed grade 3 metaplastic breast carcinoma with squamous differentiation. The tumor was triple-negative and had a high Ki-67 proliferation index. No distant metastatic site was identified in the case description.

Her multidisciplinary treatment plan was to begin neoadjuvant chemotherapy and then proceed to breast surgery. Depending on how the tumor responded, the planned operation would be either breast-conserving surgery or total mastectomy, with sentinel lymph-node biopsy. At the latest documented point, care remained at the treatment-planning stage and the planned chemotherapy and surgery had not yet been completed.