A dermal cellular non-capsulated tumor composed of irregular bundles of proliferating spindle cells with cigar-shaped or fusiform nuclei. Bundles appear to be separated by abundant amount of collagen with focal storiforms arrangement of the cells. Mitosis is not active but nuclei manifest mild anaplasia. Possibilities for this tumor include peripheral nerve sheath tumor, cellular dermatofibroma, nodular fasciitis and dermatofibrosarcoma protuberance. Marker study (SOX10, Ki67, CD34, S100, SMA and HMB-45) is recommended for definitive subtyping. Tumor appears to reach to deep margins of excision.
Scalp swelling.
Soft tissue fragment measured 1.5x1.3x1.2 cm, partially covered by skin measuring 1.3x1 cm, totally embedded.