Pleomorphic fibroma of skin. A case report and immunohistochemical study

An immunohistochemical study of a clinically benin but cytologically atypical mesenchymal lesion of the skin is presented. This lesion has been previously reported as pleomorphic fibroma and was shown to follow a benign course with a potential for local recurrence. These lesions contain occasional markedly atypical enlarged spindle cells with anaplastic-appearing nuclei. Nonmirror image mitotic figures may be present. Histogenesis of this neoplasm remains controversial with a fibroblastic origin being favored by previous authors. Our immunohistochemical findings would support this conclusion.