title: Delayed distant spinal metastasis in thymomas.
abstract: METHODS
  A case report.
  
  
  OBJECTIVE
  To demonstrate 2 cases of delayed distant spinal metastasis from a thymoma with comprehensive immunohisto-chemical analysis.
  
  
  BACKGROUND
  Thymoma is a rare slow-growing cancer arising in the mediastinum. Thymomas usually grow invasively into surrounding structures. Distal spinal metastasis is uncommon. To date, only 4 cases with histological verification have been described.
  
  
  METHODS
  Patient 1: A 42-year-old female complained about back pain for 4 years. She underwent gross-total resection of a type B2 thymoma 8 years earlier without adjuvant therapy. Neurological examination revealed no deficits. Magnetic resonance imaging demonstrated an intraspinal extradural tumor at the level of L4-S1 with infiltration of vertebral body L5. A nearly total resection was performed via a partial L4 and L5 hemilaminectomy.Patient 2: A 62-year-old female was referred with segmental thoracic pain. She underwent a total of 6 surgical procedures for resection of a thymic carcinoma during a period of 13 years with a subsequently local radiation therapy and various chemotherapy cycles. Magnetic resonance imaging revealed an intraspinal extradural tumor at the level of T9-T10 with infiltration of vertebral body T9-T10. A gross-total tumor resection was performed via a costotransversectomy and facetectomy T9-T10.
  
  
  RESULTS
  Patient 1: The tumor cells were strongly positive for AE1/3- and CK5/14-specific antibodies. Most of the immature T-cells expressed CD3. CD1a, CD5, and TdT expression was observed in a smaller portion. The findings were consistent with the diagnosis of a spinal metastasis of the known type B2 thymoma.Patient 2: The tumor cells were CK5/14 and CK19/20 positive. Only the infiltrating lymphocytes were labeled with CD3-specific antibodies. Histopathological findings revealed a metastasis of a previously resected well-differentiated thymus carcinoma.
  
  
  CONCLUSIONS
  We recommend surgical resection because metastasis of thymoma may infiltrate nerve roots and compress the spinal cord. A multidisciplinary approach is required to manage long-term sequelae.
authors: *Department of Neurosurgery, †Department of Neuropathology, Institute of Pathology, and ‡Department of Hematology, Hemostasis, Oncology, and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany.
authors: Bujung
authors: B
authors: Hong
authors: Makoto
authors: M
authors: Nakamura
authors: Christian
authors: C
authors: Hartmann
authors: Almuth
authors: A
authors: Brandis
authors: Arnold
authors: A
authors: Ganser
authors: Joachim K
authors: JK
authors: Krauss
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053547:Keratin-14 / Q000378:metabolism; D053555:Keratin-5 / Q000378:metabolism; D007796:Laminectomy; D008159:Lumbar Vertebrae / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D013125:Spinal Neoplasms / Q000378:metabolism / Q000556:secondary* / Q000601:surgery; D013904:Thoracic Vertebrae / Q000473:pathology / Q000601:surgery; D013945:Thymoma / Q000378:metabolism / Q000473:pathology*; D013953:Thymus Neoplasms / Q000378:metabolism / Q000473:pathology*
chemical_list: D053547:Keratin-14; D053555:Keratin-5