title: Epithelioid leiomyosarcoma of the external deep soft tissue.
abstract: Epithelioid leiomyosarcoma in the external deep soft tissue is extremely rare. Most epithelioid leiomyosarcomas occur in the uterus. We present a case of epithelioid leiomyosarcoma occurring in the muscle of the thigh of a 78-year-old man. Histologically, the tumor predominantly consisted of round or polygonal cells arranged in sheets with a focal spindle cell component. Immunohistochemical analysis revealed that the tumor cells expressed vimentin, alpha-smooth muscle actin, and alpha-sarcomeric actin. The tumor was negative for desmin, S100 protein, glial fibrillary acidic protein, pan-keratin, epithelial membrane antigen, CAM 5.2, HMB-45, leukocyte common antigen, factor VIII-associated antigen, and CD34. Electron microscopically, some tumor cells contained abundant actin-type filaments in their cytoplasm.
authors.affiliation: Department of Orthopaedic Surgery, Kobe University School of Medicine, Kobe, Japan. yamatetu@med.kobe-u.ac.jp
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Rieko
authors.initials: R
authors.lastname: Minami
authors.forename: Chiho
authors.initials: C
authors.lastname: Ohbayashi
authors.forename: Mayumi
authors.initials: M
authors.lastname: Inaba
mesh_terms: D008841:Actin Cytoskeleton / Q000648:ultrastructure; D000199:Actins / Q000032:analysis / Q000648:ultrastructure; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D017809:Fatal Outcome; D006801:Humans; D007150:Immunohistochemistry; D007890:Leiomyosarcoma / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008854:Microscopy, Electron; D012983:Soft Tissue Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D013848:Thigh; D014746:Vimentin / Q000032:analysis
chemical_list: D000199:Actins; D014408:Biomarkers, Tumor; D014746:Vimentin