Pigmented Extramammary Paget's Disease of the Axilla: Two Case Reports and a Literature Review

Extramammary Paget's disease is a rare intraepithelial adenocarcinoma that mainly occurs in areas rich in apocrine sweat glands, such as the vulva, perianal region, and, less commonly, in the axillary skin. Owing to the varied manifestations of extramammary Paget's disease, it is often misdiagnosed. Particularly, pigmented extramammary Paget's disease (PEMPD) can be mistaken for superficial spreading melanoma, Bowen's disease, pigmented superficial basal cell carcinoma, or seborrheic keratosis. Here, we report two cases of women with axillary pigmented plaques who were confirmed as PEMPD through histopathological and immunohistochemical analyses. One of these patients was only 31 years old, which makes her the youngest reported case of PEMPD to date. All patients underwent Mohs micrographic surgery, and no recurrence or metastasis was observed postoperatively. PEMPD is a rare clinical variant that can resemble other pigmented lesions, both clinically and histopathologically. Therefore, this report underscores the importance of accurate differential diagnosis through immunohistochemistry.