Near-complete pathological response with preoperative chemotherapy in a patient with metaplastic breast carcinoma

Metaplastic breast carcinoma (MBC) is a rare form of breast cancer comprising less than 1% of all invasive breast carcinomas. There are no clinical studies available for the management of this rare disease and MBC is associated with a poor prognosis. We present a case of a 50-year-old female patient with MBC who showed a favorable response with preoperative chemotherapy. The patient presented with a palpable left breast mass, and diagnostic breast imaging showed a 4.4 cm mass in the left breast, which was biopsied. Pathological review led to a diagnosis of MBC. Staging workup for distant metastasis was negative. She received four cycles of dose-dense AC (doxorubicin and cyclophosphamide), followed by 10 weekly doses of carboplatin (area under the curve=2) and paclitaxel (80 mg/m). The patient underwent partial mastectomy and sentinel lymph node sampling, and pathological review indicated a near-complete pathological response, with few scattered malignant cells at the tumor bed. A current review of the literature on MBC is summarized in this report.