A Case of Ectopic Extramammary Paget's Disease on the Forehead.

We report a case of ectopic primary extramammary Paget's disease (EMPD) on the forehead with positive immunohistochemical staining for cytokeratin-7 (CK7). Primary EMPD is an uncommon intraepidermal adenocarcinoma arising in the skin, primarily in apocrine gland-rich areas, most commonly in the genital and perianal regions. To our knowledge, this is the first case of EMPD reported on the forehead. There have only been four prior cases of ectopic primary EMPD reported on the face, and we provide an updated table of the prior and related cases.