ABSTRACT
The primary neuroendocrine carcinoma (NEC) of the breast is defined as immunohistochemical expression of neuroendocrine markers (chromogranin and synoptophysin) in more than 50% of the neoplastic cells according to World Health Organization (WHO) classification of tumors in 2003 (Tumours of the Breast and Female Genital Organs, 2003, Lyon: IARC Press). It accounts for less than 5% of all cancers arising from the breast (Tumours of the Breast and Female Genital Organs, 2003, Lyon, France: IARC Press). However, based on the study conducted by Wang et al., the primary NEC of breast comprises less than 0.1% of all mammary carcinomas (Frankf Z Pathol, 73, 1963, 24). Because of the rarity of the disease and absence of the prospective trials, there is no standard treatment for primary NEC of the breast. Herein, we report the case of a middle age woman with primary NEC with bone metastasis.