Fig. 8

Immunohistochemical studies. a, Immunolabeling for S-100 protein: yellow Asterix (*) denotes strong stained nerve at the periphery of the lesion while, neurofibroma tissue shows very weak immunoreactivity. b, Epithelial membrane antigen (EMA) immunostaining of laminated external sheath of the tumor, consisting, in part, of the weakly (EMA)-immunoreactive and residual perineurial sheath at the periphery of the neurofibroma (yellow arrow heads). The perineurium of a normal peripheral nerve is thin and non-stratified (black arrow head)