title: High-grade epithelioid angiosarcoma of the scalp. An immunohistochemical and ultrastructural study.
abstract: The ultrastructural and immunohistochemical characteristics of a high-grade epithelioid angiosarcoma of the scalp are reported. By light microscopy, the neoplasm simulated a poorly differentiated carcinoma, either primary or metastatic from some occult site. Immunohistochemical study, using a specific antibody against factor VIII-related antigen, was positive when direct immunofluorescence was applied to frozen specimens of the neoplasm. Application of immunoperoxidase (avidin-biotin complex method) on paraffin-embedded tissue using the same antibody was negative. Ultrastructually, the neoplasm had a prominent cytoskeleton of intermediate filaments, numerous pinocytotic vesicles, small intercellular lumina with microvilli on their surfaces, and characteristic intracytoplasmic vacuoles. A brief discussion of the differential diagnostic features is made.
mesh_terms: D000368:Aged; D000941:Antigens / Q000378:metabolism; D003593:Cytoplasm / Q000648:ultrastructure; D005169:Factor VIII / Q000276:immunology / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006394:Hemangiosarcoma / Q000648:ultrastructure*; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008854:Microscopy, Electron; D009364:Neoplasm Recurrence, Local / Q000648:ultrastructure; D012535:Scalp / Q000648:ultrastructure*; D012878:Skin Neoplasms / Q000648:ultrastructure*; D014841:von Willebrand Factor
chemical_list: D000941:Antigens; D014841:von Willebrand Factor; D005169:Factor VIII