title: Role of immunohistochemistry in the diagnosis of undifferentiated tumors involving the skin.
abstract: Twenty undifferentiated skin tumors were examined by immunostaining in an attempt to achieve more precise identification. Light microscopy yielded only a differential diagnosis, whereas immunostaining of formalin-fixed, paraffin-embedded tissue sections with a panel of antibodies to intermediate filaments and other cell components led to a definitive diagnosis. Four cytokeratin-positive epithelial tumors were subtyped into squamous cell carcinomas and adenocarcinomas with the use of antibodies to different cytokeratin polypeptides. Fifteen vimentin-positive tumors were subdivided into malignant melanomas with the use of antibody to S-100 protein, lymphomas with the use of antibody to immunoglobulin, and mesenchymal tumors (angiosarcomas, atypical fibroxanthomas, dermatofibrosarcoma protuberans, and meningiomas) with the use of antibody to S-100 protein, factor VIII, and lysozyme. One desmin-positive tumor was diagnosed as a leiomyosarcoma of the skin. A scheme is presented for using immunohistochemistry to facilitate the diagnosis of undifferentiated tumors involving the skin.
mesh_terms: D000906:Antibodies; D003893:Desmin / Q000032:analysis; D003937:Diagnosis, Differential; D004817:Epidermis / Q000032:analysis; D006651:Histocytochemistry; D006801:Humans; D007158:Immunologic Techniques; D007381:Intermediate Filament Proteins / Q000032:analysis* / Q000276:immunology; D007633:Keratins / Q000032:analysis; D009418:S100 Proteins / Q000032:analysis; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D014746:Vimentin / Q000032:analysis
chemical_list: D000906:Antibodies; D003893:Desmin; D007381:Intermediate Filament Proteins; D009418:S100 Proteins; D014746:Vimentin; D007633:Keratins