Triple-Negative Pleomorphic Lobular Breast Cancer in a BRCA1 Carrier

What happened, in summary

A 28-year-old woman with a known family BRCA1 mutation developed a left breast lump. Imaging showed a large breast mass, while staging scans found no distant metastases. Core biopsy showed a high-grade, poorly differentiated triple-negative breast cancer with features supporting a lobular origin. Genetic testing had already confirmed that she carried the familial BRCA1 pathogenic mutation.

She received neoadjuvant FEC-T chemotherapy with carboplatin and had a strong response on imaging. Because preserving fertility was important, she also received ovarian suppression during chemotherapy. After treatment, imaging showed only a residual cystic area.

She then underwent mastectomy with sentinel lymph node biopsy. Final pathology showed a complete pathologic response, with no residual breast cancer and no cancer in the 2 sampled sentinel nodes. Adjuvant radiation and delayed reconstruction were planned after surgery. Her triple-negative pleomorphic lobular cancer had responded completely to preoperative chemotherapy.