Figure 4: Photomicrographs: on pathological examination showing features of invasive ductal carcinoma (a and b); DCIS (c); and metastasis in axillary lymph nodes (d); and on immunohistochemistry showing estrogen receptor (ER) negative (e), progesterone receptor (PR) negative (f), HER2 expressed (g), and high Ki-67 (h). DCIS: Ductal carcinoma in situ