title: A case of primary small cell carcinoma of the breast.
abstract: We report a rare case of primary small cell carcinoma of the breast. A 44-year-old woman was admitted to our hospital with a mass in her left breast. Fine-needle biopsy revealed small cell carcinoma with neuroendocrine differentiation resembling small cell carcinoma of the lung. Systemic computed tomography (CT) and magnetic resonance imaging (MRI) revealed no primary site in the lung or any other organ. A modified radical mastectomy with removal of the axillary lymph node (Bt + Ax, R2) was performed. Histological examination revealed that the tumor was composed of small round to oval cells with a large nuclear-cytoplasmic ratio. The tumor cells were positive for neuroendocrine differentiation markers such as synaptophysin, CD56, and neuron-specific enolase (NSE), but negative for thyroid transcription factor-1 (TTF-1), leukocyte common antigen (LCA), estrogen receptor (ER), and progesterone receptor (PR). Interestingly, the tumor cells lacked immunoreactivity for epithelial markers, including cytokeratin AE1/3, CAM5.2, and epithelial membrane antigen (EMA). The patient was given adjuvant chemotherapy for axillary lymph node metastasis. There were no signs of recurrence 22 months after surgery.
authors.affiliation: Division of Surgical Oncology, Cancer Research Institute, Kanazawa University, Japan.
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Kitakata
authors.forename: Kazuo
authors.initials: K
authors.lastname: Yasumoto
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Sudo
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Minato
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Takahashi
mesh_terms: D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001365:Axilla / Q000473:pathology; D015415:Biomarkers / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D018278:Carcinoma, Neuroendocrine / Q000378:metabolism / Q000473:pathology*; D018288:Carcinoma, Small Cell / Q000378:metabolism / Q000473:pathology*; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000473:pathology
chemical_list: D015415:Biomarkers