title: Subcutaneous malignant epithelioid schwannoma with cartilaginous differentiation.
abstract: BACKGROUND
  Malignant epithelioid schwannoma is a rare tumor. The aim of this study is to describe a case of subcutaneous malignant epithelioid schwannoma with cartilaginous differentiation.
  
  
  METHODS
  Histological, immunohistochemical, and ultrastructural examinations were performed on a tumor that arose on the back of a 37-year-old woman.
  
  
  RESULTS
  Histologically, the tumor predominantly consisted of small, round or polygonal cells arranged in cords or nests. Immunohistochemical study revealed that the tumors cells were positive for vimentin, S-100 protein, glial fibrillary acidic protein and neuron specific enolase. The cells were negative for HMB-45, keratin, epithelial membrane antigen, and CAM5.2. Electron microscopic study showed closely associated cells with undifferentiated features. The cells were devoid of external laminae and cellular junctions.
  
  
  CONCLUSIONS
  Malignant epithelioid schwannoma should be pathologically differentiated from other epithelioid tumors with cartilaginous elements.
authors.affiliation: Department of Orthopaedic Surgery, Kobe University School of Medicine, Kobe, Japan. yamatetu@med.kobe-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.forename: R
authors.initials: R
authors.lastname: Minami
authors.forename: C
authors.initials: C
authors.lastname: Ohbayashi
mesh_terms: D000328:Adult; D002356:Cartilage / Q000473:pathology*; D002454:Cell Differentiation; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008854:Microscopy, Electron; D018317:Nerve Sheath Neoplasms / Q000473:pathology*; D009442:Neurilemmoma / Q000473:pathology*