Primary neuroendocrine carcinoma of the breast: A single Center experience and review of the literature

Neuroendocrine carcinoma of the breast is an extremely rare tumor. A standard treatment has yet to be established because only a few cases have been reported in literature. The authors report five cases observed from January 2007 to December 2014 and a review of literature. Four patients underwent quadrantectomy and in two cases axillary nodal dissection and only one to mastectomy with axillary nodal dissection. Tumor size was from T1 to T2 with N0 to N1, according TNM classification. Pathological specimens were stained with hematoxylin and eosin and an immunohistochemical panel of antibodies (Neuron-specific enolase, Chromogranin, Synaptophysin, Estrogen and Progesterone receptors, c-erb and Ki-67). All cases showed markers positivity to Neuron-specific enolase, Chromogranin, Synaptophysin and Estrogen and Progesterone receptors were found. Ki-67 was higher than 40% in four patients. Adjuvant chemotherapy was administrated in patients with Ki-67 > 10%; every patients were treated with radiotherapy and with hormonal therapy too. Although Neuroendocrine breast tumor is considered a distinct entity, the best treatment seems to be correlate to the size of tumor and to the lymph node status and to Ki-67 index like the common breast cancer.