Fig. 2.
Spindle cell neoplasm showing alternating celular and less celular areas (tapestry pattern) and geographical necrosis. HE, 4X (A). Focal positivity for S100 protein, showing up Schwann cell differentiation. S100 IHC, 10X (B). Focal positivity for myogening, evidencing skeletal muscle differentiation. Myogenin IHC, 10X (C).