Metaplastic Breast Carcinoma in a 37-Year-Old Female: A Case Report

Metaplastic breast carcinoma (MBC) is a rare and aggressive histologic subtype of cancer. Because of its rarity and heterogeneity, the management of these patients is challenging. Here, we present the case of a rapidly progressive MBC with mesenchymal differentiation in a 37-year-old female, treated with trimodal therapy consisting of neoadjuvant chemotherapy with paclitaxel and carboplatin, followed by dose-dense cyclophosphamide and doxorubicin (ddAC), modified radical left mastectomy, and adjuvant radiotherapy. Despite the need to anticipate the surgery after the first cycle of ddAC, because of a life-treating adverse event, there was a pathologic complete response. Nevertheless, 6.2 months after completing adjuvant radiotherapy, the patient had a recurrence on the central nervous system (CNS) (two lesions), which was managed with excisional biopsy and stereotactic body radiation therapy. The patient also started "complementary" chemotherapy with capecitabine. Still, 18 months after being diagnosed, she died due to CNS disease progression.