It can be differentiated from benign fibrous histiocytoma or diffuse/pigmented neurofibromas by positive CD34 expression in tumor cells; (2) Fibrosarcomatous DFSP: In some cases, tumor cells show severe atypia, visible mitotic figures, and appear as elongated bundles or fishbone-like arrangements, similar to fibrosarcoma. The gene discussed is CD34; the disease is benign fibrous histiocytoma.