Extramammary Paget Disease.

Extramammary Paget disease is an intraepidermal adenocarcinoma, most often limited to the epidermis, with typical cases affecting genital skin. When limited to the epidermis, primary extramammary Paget disease is not life-threatening, but invasive disease may portend a poor prognosis. Surgical excision remains the mainstay of treatment of extramammary Paget disease, and Mohs micrographic surgery is the surgical treatment of choice. Alternative treatments include topical 5-fluorouracil and imiquimod, photodynamic therapy, laser vaporization, chemotherapy, and radiation therapy but data are limited. Implementation of cytokeratin 7 immunostain has increased the ability to detect extramammary Paget disease on frozen section.