Fig. 9.

A 62-year-old female with right primary neuroendocrine carcinoma of the breast. Low (left) and high (right) magnification hematoxylin and eosin stains from 11 o’clock right breast core biopsy. Low magnification demonstrates nests and solid sheets of cells with rounded margins separated by fibrovascular stroma. High magnification demonstrates neoplastic cells which are uniform in shape and size with increased nuclear cytoplasmic ratio, hyperchromatic nucleus, and scant cytoplasm. These pathologic findings are highly characteristic of a primary neuroendocrine carcinoma of the breast.