Fig. 2

Preoperative histopathological findings. Histopathological findings of the right breast from core needle biopsy [a hematoxylin and eosin (HE) ×200]. Immunohistochemistry study for ER and HER2 (b ER ×200 and ×400, c: HER2 ×200). The cytology of the right axillary lymph node from fine needle aspiration cytology (d Papanicolaou ×400). Atypical ductal cells, ER-weakly positive (1–5%) and HER2-positive, formed solid nest with sheet-like growth. Atypical epithelial clusters with hyperchromatic nuclei were seen in red blood cells and lymphocytes