A single pedunculated slowly growing tumor was found on the right thigh of a 49 year-old woman. The tumor cells were largely those of eccrine poroma but the degree of the extension of the tumor cell masses, which occupied most of the dermis, were like that of invasive basal cell epithelioma. In addition there were areas where the cells show considerable atypia and dyskeratosis. These histopathological findings were compatible with eccrine poroepithelioma first reported by Mishima and Morioka(1969). The histologic differences between eccrine poroma, eccrine poroepithelioma and eccrine porocarcinoma were discussed.
Carcinoma, Basal Cell ; Dermis ; Eccrine Porocarcinoma ; Female ; Humans ; Middle Aged ; Poroma ; Thigh