ERBB2 and extramammary Paget disease: Herein, we report an elderly male case of advanced EMPD with human epidermal growth factor receptor 2 (HER-2) overexpression combined with sweat gland carcinoma, sequentially received first-line chemotherapy and second-line anti–HER-2 Antibody-drug conjugates (ADC) drug treatment, followed by third-line treatment with third-line pan-HER family receptor tyrosine kinase inhibitor pyrotinib (Pyrotinib).