Histological examination of a punch biopsy specimen of a slowly growing, irregular dermal tumour from the right lower leg of a 32-year-old woman, which had been diagnosed clinically as a dermatofibrosarcoma protuberans, showed it to be a deep penetrating dermatofibroma. The diagnosis was established by characteristic histological and immunohistochemical criteria. This allowed sequential excision in two sessions with primary closure and an optimal cosmetic result.