Metaplastic spindle cell carcinoma of the breast in a patient with neurofibromatosis type 1

We report a unique case of a 67‐year‐old woman with neurofibromatosis type 1, who was also diagnosed with metaplastic spindle cell carcinoma of the left breast. She had many neurofibromatosis lesions on her body, as well as the mass in the left breast. After the breast mass was diagnosed as a malignant mesenchymal tumor by core needle biopsy, the patient underwent left modified radical mastectomy. Subsequently, the pathological analysis of the tumor showed it to be a metaplastic spindle cell carcinoma. The co‐occurrence of neurofibromatosis type 1 and breast cancer, in particular metaplastic spindle cell carcinoma, is very rare.