[A case of perineal (extramammary) Paget's disease].

A case of perineal Paget's disease in a 67-year-old male patient is reported. The perineal polyp, having shown no increase in size for 3 years, wks resected. The microscopic features of the polyp was comprised of clusters of a pale, large tumor cell (Paget cell) only in the epidermis. The skin that was resected around the polyp showed almost the same histological appearance as the polyp, except for an infiltration of tumor cells forming a small gland structure on the minimal region of the dermis. Both the Paget's cells and these tumor cells showed positive for mucin staining. Ultrastructurally, we confirmed two types of Paget's cells, one containing much granules and the other lacking in these granules but rich in other organelles. Further, the Paget's cells formed lumen and intercellular canaliculus, suggesting a differentiation to the eccrine sweat gland. From our findings and a review of the literature, we favor presuming that extramammary Paget's disease without a cancer of the neighbouring organs originates from the epidermis and extends to the dermis.