title: [Clinicopathologic characteristics of primary Schwannoma of the bone].
abstract: OBJECTIVE
  To evaluate the diagnostic criteria and morphologic difference of primary schwannoma from that of soft tissue schwannoma.
  
  
  METHODS
  All neurogenic tumors of the bone in this hospital from 2002 to 2013 were reviewed, four cases of primary schwannoma arising from bone were selected. Their clinical features, radiologic appearance and pathologic findings were evaluated. Immunophenotyping was performed using EnVision method.
  
  
  RESULTS
  All four cases had classic morphologic features and immunophenotype of conventional schwannoma. Compared with schwannoma of the soft tissue, primary bone schwannoma had the following features: benign radiological appearance, absence of capsule under light microscope, local infiltration of bone or destruction of bone cortex, occasionally involving extra-osseous soft tissue. Most tumors were solid, with less cystic degeneration. Histologically, the tumors were mainly composed of compact areas of spindle cells (Antoni A), and areas of hypercellularity could often be observed.
  
  
  CONCLUSIONS
  Primary schwannoma of the bone is rare, usually arises within the long bones and flat bones. Compared to conventional soft tissue schwannoma, it shows different growth pattern, imaging and pathologic features; thus care should be exercised not to misdiagnose schwannoma of the bone as other primary low-grade malignant spindle cell sarcoma of the bone and to avoid unnecessary over-treatment.
authors.affiliation: Department of Pathology, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai 200233, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Jiao
authors.affiliation: Department of Pathology, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai 200233, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Huang
authors.affiliation: Department of Pathology, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai 200233, China.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: Department of Pathology, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai 200233, China. E-mail: liuyuanblz@aliyun.com.
authors.forename: Huizhen
authors.initials: H
authors.lastname: Zhang
mesh_terms: D001859:Bone Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D016130:Immunophenotyping; D009442:Neurilemmoma / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D011859:Radiography; D012509:Sarcoma / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000473:pathology