Figure 4. Immunohistochemical analysis showed tumor cells with multifocal positivity for A) Desmin (400x) and B) smooth muscle actin (SMA) (200x) in a subset of neoplastic cells, while caldesmon, SOX-10, and SATB2 were negative. Additionally, the melanoma markers (Melan A and HMB45) and epithelial (CK AE1:AE3) immunostains were negative.
