Breast carcinosarcoma is an aggressive subtype of cancer that accounts for less than a percent of all breast malignancies. Carcinosarcoma is difficult to diagnose and treat. In the following, we present a case of breast carcinosarcoma with the treatment method.

An extremely rare form of breast cancer, breast carcinosarcoma accounts for less than a percent of all breast malignancies and is highly aggressive. Composed of both cancerous epithelial and mesenchymal cell types, breast carcinosarcoma is associated with a poor prognosis compared to more common breast cancers, and typically lack the receptors typical of other breast carcinomas, which minimize potential targets for treatment. In this case report, we discuss a 56‐year‐old patient affected by carcinosarcoma of the breast at a T2N1 stage, and the decision‐making process that factored into her treatment plan.