A case of solid neuroendocrine carcinoma of the breast

Abstract

A woman in her 70s noticed a mass in her right breast and visited our hospital. A 17 mm mass was observed in the E region (nipple-areola region) of her right breast. Mammography revealed a high-density, spiculated mass. Ultrasonography revealed a globular, 15 mm low-echoic mass. When fine-needle aspiration cytology was performed, invasive ductal carcinoma (solid-tubular carcinoma) was suspected. Since the cells had light-green stained, finely granular cytoplasm, the possibility of neuroendocrine differentiation was also considered. A needle biopsy was performed and the tumor was positive for chromogranin A, CD56 and synaptophysin, indicating the presence of neuroendocrine carcinoma. Consequently, the patient was diagnosed with neuroendocrine carcinoma. After a right-sided mastectomy and a sentinel lymph node biopsy were performed, the diagnosis of neuroendocrine carcinoma was confirmed.