A Case of Pigmented Mammary Paget's Disease

Pigmented mammary Paget's disease is a uncommon clinicopathologic variant of mammary Paget's disease, and this mimics malignant melanoma both clinically and histopathologically. Herein, we report on a rare case of pigmented mammary Paget's disease. An 81-year-old woman presented with 2.5x1 cm sized, red and brown, eczematous plaque on her right areola, and she'd had this lesion for 3 years. Histopathology showed large, atypical cells with large nuclei and abundant pale cytoplasm throughout the epidermis. Dispersed melanocytes; were noted in the epidermis and some of the Paget's cells contained melanin within their cytoplasm. Immunohistochemical studies demonstrated that the intraepidermal pagetoid cells were positive for cytokeratin 7; in contrast, they were negative for S-100, Periodic-acid Schiff (PAS), Alcian blue at PH 2.5, HMB-45 and carninoembryonic antigen (CEA). We recommend that pigmented mammary Paget's disease should be included in the differential diagnosis of pigmented lesions on the nipple.