Primary neuroendocrine breast carcinoma: A rare case report.

Primary neuroendocrine carcinoma of the breast is a very rare occurrence accounting for <0.1% of all breast cancers. For the diagnosis, it requires the diffuse expression of neuroendocrine markers (chromogranin, synaptophysin, neuron-specific enolase) and the lack of simultaneous neuroendocrine carcinoma in extramammary sites. The breast carcinomas with focal neuroendocrine differentiation are defined as scattered tumor cells that stain positive with neuroendocrine markers. These tumors are usually seen in elderly women around sixth or seventh decade of life, as reported in literatures. The high nuclear grade and regional lymph node metastasis was also significant negative prognostic factors for overall survival. We study a case of primary neuroendocrine carcinoma of breast in a 46-year-old lady, on the basis of histopathology and immunohistochemistry. [ABSTRACT FROM AUTHOR]