HER-2 positive primary solid neuroendocrine carcinoma of the breast: a case report and review of the literature.

Primary pure neuroendocrine carcinoma of the breast is an extremely rare tumor. We report a case of primary solid neuroendocrine carcinoma in a 77-year-old postmenopausal woman who was admitted to the hospital with masses on her right breast and axillary region. Radical mastectomy with axillary lymph node resection was performed. Immunohistochemical stainings of the tumor cells with synaptophysin, GCDFP-15, estrogen, progesterone, and c-erbB-2 were positive. Five of 16 lymph nodes were metastatic. She did not receive adjuvant chemotherapy. After 15 months of follow-up she is free of the disease. Literature review revealed that this is the second case of HER-2 positive primary neuroendocrine tumor of the breast.