A Case of Neuroendocrine Tumor of the Breast with Bloody Nipple Discharge

Abstract

A relatively rare case of neuroendocrine tumor of the breast was reported.
A 67-year-old female visited the out-patient clinic at our hospital complaining of bloody discharge flowing from the nipple of her right breast in March 2010.
The bloody discharge flowed from her right nipple when a trigger point on the D-region of her right breast was pressed.
Several supplemental diagnostic examinations were performed, but the exact diagnosis could not be confirmed and her clinical course was therefore followed.
After 11 months from the first medical examination a 3cm diameter tumor in the D-area of the right breast was palpable.
The tomor was suspected to be breast cancer by the findings of mammary ductography and fine needle aspiration biopsy cytology.
Ultrasound-guided core needle biopsy was then performed to obtain the exact diagnosis and breast cancer was able to be diagnosed.
A neuroendocrine tumor was suspected on the basis of immunohistochemical examinations.
A right modified radical mastectomy and axillary lymph node dissection were performed.
Histopathologically，most of the tumor consisted of noninvasive ductal carcinoma that had partially invaded surrounding fatty tissues.
Tumor cells showed clear, eosinophilic cytoplasm and contained oval or spherical nuclei with fine granulated chromatin and were formed into a pseudorosette arrangement.
Nucleal atypia of the tumor cells was grade 1. The tumor was clearly diagnosed as a neuroendocrine tumor because the majority of tumor cells were stained strongly positive by immunochemical staining (Chromogranin A and Synaptophysin).
The tumor showed neither vessel invasion nor signs of axillary lymph node involvement.
Immunohistochemically, estrogen receptor and progesterone receptor were positive and human epidermal growth factor receptor 2 was negative.
Based on the above findings, the patient was administerd aromatase inhibitor (anastrozole) for five years. and remains well without any signs of recurrence as of May 2016.