RESUMEN
Primary neuroendocrine carcinoma of the breast is a rare disease that accounts for less than 5% of all cancers arising from the breast. The tumour cells stain positively for chromogranin and synaptophysin. This report describes the occurrence of infiltrating ductal carcinoma of breast with neuroendocrine differentiated tumour in 37 year old female. Early small cell neuroendocrine cancer of the breast that is treated with surgery and adjuvant chemotherapy shows an increased disease-free survival. She is planned for anthracycline/cyclophosphamide based chemotherapy followed by etoposide/platinum based chemotherapy. As her tumour showed ER/PR positivity, she will be given hormonal therapy subsequently, however, more extensive review is required to define a standard treatment protocol for this rare neoplasm.