We report an unusual case of primary scrotal extramammary Paget disease that infiltrated reticular dermis and lymph vessels, with metastasis in inguinal lymph node. The 67-year-old patient died at 14 months due to systemic metastases. The tumor, which was located in epidermis and infiltrated the dermis, comprised cells with wide, granular, and eosinophilic cytoplasm and intense positivity for antimitochondrial antibody. This seems to be the first report of oncocytic changes in extramammary Paget disease.