IMMUNOHISTOCHEMICAL DETECTION OF P53 IN EPIDERMAL PROLIFERATIONS OVERLYING DERMATOFIBROMAS

Basaloid proliferations of epidermis overlying dermatofibromas and mor phologically resembling superficial basal cell carcinomas might posses s a malignant potential, In order to elucidate whether these basaloid proliferations share phenotypic characteristics with malignancy, we ex amined immunohistochemically 19 cases of dermatofibroma with overlying epidermal basaloid proliferations, 10 dermatofibromas with overlying simple epidermal proliferations, and 10 invasive basal cell carcinomas for expression of p53. Simple and basaloid proliferations showed spar se positive immunostaining for p53, as seen in normal epidermis, No di fferences in staining pattern or number of positive keratinocytes coul d be demonstrated between these conditions, The dermatofibromas were n egative. The invasive basal cell carcinomas showed abundant p53 positi vity, The lack of p53 immunoreactivity in the epidermal basaloid proli ferations overlying dermatofibromas indicates that these lesions have not acquired a phenotype as seen in malignant conditions.