fig2

Figure 2. Expression of HER2 protein. A negative HER2 immunostaining in a primary infiltrative ductal carcinoma (a, ×160) became positive in the lymph node metastasis (positive conversion) (b, ×120). The strong and complete HER2 immunoreactivity in a case of primary BC (c, ×200) was not present in the synchronous lymph nodal metastasis (negative conversion) (d, ×200) (IHC, Mayer's hematoxylin counterstain). HER2: Human epidermal growth factor receptor 2; BC: Breast carcinoma; IHC: Immunohistochemistry