Neuroendocrine Carcinoma of the Breast Encountered in the General Hospital without the Breast Department-A Case Report

Neuroendocrine carcinoma(NEC)is a rare disease. We report a case of NEC encountered in the general hospital without a breast department. The patient was a 69-year-old woman. She had received breast cancer screening and a mass on her left breast was found. Mammography revealed an ill-defined mass. Ultrasonography showed a low echoic mass, 11mm in diameter, on the A area of her left breast. A core needle biopsy of the breast tumor(A area)led to a diagnosis of an invasive ductal carcinoma, positive for estrogen receptor and progesterone receptor, but negative for HER2/neu. The Ki-67 positive cell index was 5%. We then examined her whole body and diagnosed her with T1N0M0, Stage Ⅰ. She underwent muscle-preserving mastectomy plus sentinel lymph node biopsy. The pathological diagnosis from the resected surgical specimen was invasive ductal carcinoma(NEC), positive for estrogen receptor and progesterone receptor, but negative for HER2/neu. The Ki-67 positive cell index was 5%. The surgical margins were negative, and no metastasis was found in the sentinel lymph node. She was administered endocrine therapy as adjuvant therapy. Two years postoperatively, she was well without metastases.