Metaplastic Carcinoma of the Breast with Neuroectodermal Stromal Component

A unique case of metaplastic breast carcinoma with an epithelial component showing tumoral necrosis and neuroectodermal stromal component is described. The tumor grew rapidly and measured 9？cm at the time of diagnosis. No lymph node metastases were present. The disease progressed rapidly and the patient died two years after the diagnosis from a hemorrhage caused by brain metastases. The morphology and phenotype of the tumor are described in detail and the differential diagnostic options are discussed. 1. Introduction Metaplastic breast carcinoma is a rare tumor and represents a heterogeneous group of lesions. According to the World Health Organization (WHO) classification, these lesions are divided into purely epithelial and mixed epithelial—mesenchymal tumors, with the latter called carcinosarcoma when the mesenchymal component is malignant [1, 2]. The mesenchymal component of carcinosarcomas most often exhibit chondroid, osteoid, or rhabdoid differentiation, and neuroid differentiation of this component is extremely rare. In this paper, we present a unique case of metaplastic breast carcinoma with an epithelial component showing tumoral necrosis and neuroectodermal mesenchymal component. 2. Clinical History The patient was a 53-year-old Kurdish woman with a large, rapidly growing mass in her right breast, but who was otherwise healthy. The patient had no family history of breast cancer, had given birth to seven children, and was still menstruating. At the time of presentation, the patient had a hard 9？cm tumor in her right breast that was visible on inspection. There were no palpable nodes in the axilla. Mammography showed a multinodular tumor, the largest nodule being 65？mm, with calcifications. Ultrasound confirmed the presence of a well circumscribed nodular tumor with mixed echogenicity and revealed enlarged pathological nodes in the axilla. A preoperative core needle biopsy of the breast lesion showed structures of an obviously malignant small cell tumor with a high proliferation index, and it was negative for estrogen and progesterone receptors and HER-2. preoperative neoadjuvant chemotherapy was given: three cycles of epirubicin and docetaxel, followed by three cycles of docetaxel. However, no substantial tumor remission was observed, and after five cycles a mastectomy and axillary lymph node dissection was performed. Because of the poor response to neoadjuvant chemotherapy, it was decided to give four cycles of carboplatin and gemzitabin (after a negative bone scan and computed tomography of the thorax and abdomen) followed by radiotherapy to