Primary Small Cell Carcinoma of the Breast

• Published in: Nihon Rinsho Geka Gakkai Zasshi (Journal of Japan Surgical Association) Vol. 80; no. 7; pp. 1284 - 1290
• Main Authors: ZAIMOKU, Ryosuke, KIRIYAMA, Masato, TAKEI, Ryohei, KANAMOTO, Ayako, HIGASHI, Yuki, TSUKIOKA, Yuji
• Format: Journal Article
• Language: Japanese
• Published: Japan Surgical Association 2019
• Subjects: breast cancer; chemotherapy; small cell carcinoma
• ISSN: 1345-2843; 1882-5133
• DOI: 10.3919/jjsa.80.1284

A 52-year-old woman was admitted to our hospital because of a mass in the upper area of the left breast, and ultrasonographic examination showed a hypoechoic mass in the same area. The histological findings of the mass by a large needle biopsy showed dense proliferation of undifferentiated small cells with a high nuclear-to-cytoplasmic ratio, and immunohistochemical findings revealed that the tumor cells were focally positive for CD56. So, the tumor was diagnosed as primary small cell carcinoma of the breast. The patient had no regional nodal metastases, distant metastases and non-mammary primary site. She underwent left modified radical mastectomy with sentinel lymph node biopsy, followed by adjuvant chemotherapy with epirubicin/cyclophosphamide followed by weekly paclitaxel therapy. At this writing, the patient has evidenced no recurrence 7 month after the operation.Primary small cell carcinoma of the breast is an exceptionally rare type of mammary neoplasm, so its treatment is poorly understood. Here, we report a case of primary small cell carcinoma of the breast with a review in the literature.