title: Dedifferentiated chondrosarcoma with leukocytosis and elevation of serum G-CSF. A case report.
abstract: BACKGROUND
  G-CSF is known to function as a hematopoietic growth factor and it is known to be responsible for leukocytosis. G-CSF-producing tumors associated with leukocytosis include various types of malignancies.
  
  
  METHODS
  We report the case of a 72-year-old man with dedifferentiated chondrosarcoma characterized by dedifferentiated components of malignant fibrous histiocytoma- or osteosarcoma-like features in addition to conventional chondrosarcoma, arising from his pelvic bone. After hemipelvectomy, when local recurrence and metastasis were identified, leukocytosis appeared and an elevated level of serum granulocyte-colony-stimulating factor (G-CSF) was also recognized. The patient died of multiple organ failure 2 months after surgery. Autopsy specimens showed that the histological specimens of the recurrence and metastasis were dedifferentiated components, without any conventional chondrosarcoma components. G-CSF was expressed only in the dedifferentiated components, not in the chondrosarcoma components, immunohistochemically.
  
  
  CONCLUSIONS
  This is the first report of chondrosarcoma, or any other primary bone tumor, with leukocytosis, probably stimulated by tumor-produced G-CSF from the dedifferentiated components.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan. akio@med.kyushu-u.ac.jp
authors.forename: Akio
authors.initials: A
authors.lastname: Sakamoto
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Tanaka
authors.forename: Shuichi
authors.initials: S
authors.lastname: Matsuda
authors.forename: Katsumi
authors.initials: K
authors.lastname: Harimaya
authors.forename: Yoshinao
authors.initials: Y
authors.lastname: Oda
authors.forename: Masazumi
authors.initials: M
authors.lastname: Tsuneyoshi
authors.forename: Yukihide
authors.initials: Y
authors.lastname: Iwamoto