The positivity for CD99 and BCL2 in this case suggests that the tumor is quite different from classic myofibroblastic proliferations, such as nodular fasciitis, fibromatosis, and dermatofibroma, as well as from benign and malignant smooth muscle proliferations, which are all uniformly negative for these antigens. This evidence concerns the gene CD99 and cutaneous fibrous histiocytoma.