Ectopic extramammary Paget's disease arising on the cheek

BACKGROUND. Extramammary Paget's disease (EMPD) is a rare neoplasm affecting apocrine gland-bearing skin. Patients usually present with a long-standing unilateral, ill-defined, erythematous or whitish-gray, crusted patch or plaque. This tumor almost never occurs outside of the anogenital or axillary areas. OBJECTIVE. We report the first case of "ectopic" extramammary Paget's neoplasm afflicting the face. METHODS. The excisional specimen from a 67-year-old man was reviewed. Histology and immunohistochemistry studies were performed on the specimen. RESULTS. Histology revealed hyperkeratosis, parakeratosis, acanthosis, and proliferation of cytologically atypical epithelioid cells permeating the epidermis and the cutaneous adnexae. Special stains showed reactivity to cytokeratins (AE1/AE), epithelial membrane antigen, and carcinoembryonic antigen in the atypical cells. There was no evidence of apocrine glands in the area. CONCLUSION. Herein we present the first case of truly "ectopic" extramammary Paget's disease on the face.