A rare case of extramammary Paget's disease of bilateral axillae with adenocarcinoma was reported. A 82-year-old woman had noticed the erythematous macules on her both axillae three years ago. A subcutaneous mass and a number of swollen lymph nodes were detected under the erythematous macule surrounded by pigmentation or depigmentation on her right axilla. There was no evidence of breast carcinoma on the initial examination. Both lesions were widely excised including the regional lymph nodes of the right axilla. The lesion of the right histopathologically showed a well demarcated nest of adenocacinoma in the dermis through the subcutaneous fat tissue. The overlying epidermis was involved by Paget cells. In the vicinity of the tumor nest, some components of supernumerary mammary glands showing positive immunohistochemical staining for anti-estrogen receptor antibody were found. The left axillary lesion histopathollogically showed Paget's cell infiltration in epidermis and the presence of components of supernumerary mammary glands in the deep dermis. The relationship among the Paget's cell, supernumerary mammary glands and adenocarcinoma was discussed. [Skin Cancer (Japan) 2000; 15:121-125]
