CD34 and dermatofibrosarcoma protuberans: Dermatofibrosarcoma protuberans, a highly cellular, low-grade tumor, is a good example of skin neoplasms formed by cells of mesenchymal lineage that express CD34 [64,65,66], The CD34+ neoplastic cells are spindle-shaped (Figure 12A–C), show little pleomorphism and are arranged in interwoven fascicles, giving the lesion a storiform or intersecting (cartwheel) pattern (Figure 12A).