title: Solitary cutaneous malignant schwannoma. Immunohistochemical and ultrastructural studies.
abstract: We describe two cases of malignant schwannoma in the skin that did not originate from a nerve trunk and was not associated with neurofibromatosis. Light microscopy showed that both tumors were composed predominantly of atypical spindle-shaped cells. Immunohistochemical analysis was performed with various monoclonal antibodies against mesenchymal determinants. In both patients, tumor cells were positive for S-100 alpha and S-100 beta, neuron-specific enolase, vimentin, neurofilament protein, and myelin basic protein, and negative for HMB-45, glial fibrillary acidic protein, epithelial membrane antigen, and desmin. Electron microscopy revealed that the tumor cells possessed indented nuclei with an electron-lucent cytoplasm. Immunoelectron microscopy showed diffuse fine granular staining for S-100 alpha, not detectable in normal Schwann cells, in the cytoplasm of the tumor cells.
authors.affiliation: Department of Dermatology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Kikuchi
authors.forename: M
authors.initials: M
authors.lastname: Akiyama
authors.forename: H
authors.initials: H
authors.lastname: Han-Yaku
authors.forename: H
authors.initials: H
authors.lastname: Shimizu
authors.forename: W
authors.initials: W
authors.lastname: Naka
authors.forename: T
authors.initials: T
authors.lastname: Nishikawa
mesh_terms: D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis; D009442:Neurilemmoma / Q000737:chemistry* / Q000648:ultrastructure*; D012878:Skin Neoplasms / Q000737:chemistry* / Q000648:ultrastructure*
chemical_list: D009363:Neoplasm Proteins