SOX10 and malignant peripheral nerve sheath tumor: Pathology confirmed a high grade spindle cell sarcoma, negative for S100 protein and SOX10 (variable expression in MPNST), Desmin (rhabdomyosarcoma differentiation), CD31 and AE1:AE3 (vascular sarcomas, myoepitheliomas), HMB45, MelanA (epitheloid MPNST).