ERBB2 and extramammary Paget disease: The immunohistochemical study (Table 1) was positive for human epidermal growth factor receptor 2 (Her2 or Neu; Figure 2c), carcinoembryonic antigen (CEA; Figure 2d), cytokeratin-7 (CK7; Figure 2e), and gross cystic disease fluid protein of 15kDa (GCDFP-15; Figure 2f), confirming the diagnosis of EMPD.