Primary Neuroendocrine Tumor of Breast: Report of a Rare Case with Review of Literature

Abstract

The neuroendocrine tumors (NETs) are basically derived from the neuroendocrine cell which secrete different types of amines and peptides. The neuroendocrine cell is very rare in breast carcinoma of less than 0.1%. In the breast carcinoma, Primary neuroendocrine tumors are a heterogeneous series with 50% of cells having positive immunoreactivity to neuroendocrine markers.A case of 52 years woman with a lump in her right breast. She was evaluated for surgery and modified radical mastectomy (MRM) was done. Grossing of specimen showed two tumors in retro areolar and lower outer quadrant respectively. Histopathology revealed neuroendocrine tumor of the breast. All eighteen lymph nodes showed reactive lymphoid hyperplasia. Immunohistochemical report showed cells were positive for synaptophysin, chromogranin, neuron specific enolase (NSE) and Ki67 (60-70%). The estrogen receptor, progesterone receptor and HER-2Neu were negative. No mucin production was seen in this patient.Neuroendocrine tumors in the breast are mostly malignant. Mucinous carcinomas of breast have association with neuroendocrine differentiation but in this case although having neuroendocrine differentiation, is not associated with mucin production. Here we present a case of NET of the breast where tumor cells were non-reactive for ER (Estrogen Receptor), PRs (Progesterone Receptors) and cells show frequent mitotic figures. The review accompanying this case report is provide an overview of all the cases of primary neuroendocrine tumor of the breast published in the literature and detailed information regarding classification, epidemiology, clinical and histological diagnosis criteria, histogenesis, surgical and adjuvant treatment, as well as prognosis.