Abstract: A 34-year-old man presented with bean-sized papules on his nostril and broad bean-size nodule on his scrotum for two months. The primary dignosis was tumor and the patient was planned to treat by surgery. The preoperative blood test showed TPPA≥1∶2560, TRUST:1∶4 and positive of TPAB-ELISA. The biopsy of his scrotal nodules revealed that epidermal process hyperplasia, keratinous material in the epidermis, a massive infiltration of plasma cells in the the upper dermis. The diagnosis of secondary syphilis was made.

Key words: secondary syphilis, misdiagnose, dermoscopy