title: Ectopic primary type A thymoma located in two thoracic vertebras: a case report.
abstract: BACKGROUND
  The thymus arises in the ventral portion of the third and fourth pharyngeal pouch. It descends into the anterior mediastinum at 6th week of gestation. Any errors occurring during this process can cause dissemination of aberrant nodules that are responsible for most atypical thymomas.
  
  
  METHODS
  The authors report a unusual case of type-A thymoma located in D10 and D11 vertebral bodies.The histology showed a uniform growth of short, spindle shaped, mitotically inactive cells. A few small, normal lymphocytes were seen scattered or in small groups. The immunohistochemical investigation for neuroectodermal, neuroendocrine, vascular and muscular markers were negative. It also confirmed the presence of CD3+, CD5+ T lymphocytes and the absence of immature T-lymphocyte markers.
  
  
  CONCLUSIONS
  The case described shows a thymic hystogenesis for spindle cell tumours. To our knowledge no other cases of vertebral thymomas have been described in international literature.
authors.affiliation: Department of Surgical Pathology, Regina Elena Cancer Institute, 00144, Rome, Italy. marandino@ifo.it
authors.forename: Ferdinando
authors.initials: F
authors.lastname: Marandino
authors.forename: Carmine
authors.initials: C
authors.lastname: Zoccali
authors.forename: Nicola
authors.initials: N
authors.lastname: Salducca
authors.forename: Mirella
authors.initials: M
authors.lastname: Marino
authors.forename: Paolo
authors.initials: P
authors.lastname: Visca
mesh_terms: D001416:Back Pain / Q000209:etiology; D003475:Curettage; D003582:Cytogenetics; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007796:Laminectomy; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D013125:Spinal Neoplasms / Q000150:complications / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D013904:Thoracic Vertebrae / Q000473:pathology* / Q000601:surgery; D013945:Thymoma / Q000150:complications / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome