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.

Case presentation: 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.

Conclusion: 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.

Figure 1

Roentgenographs show an expansive lesion with punctate calcification in the right pelvic bone (left). MRI shows a lobulated lesion, protuberant to the pelvic cavity, in the pelvic bone with high-intensity on T2-weighted image (right).

Figure 2

Dedifferentiated chondrosarcoma; well-differentiated components show conventional chondrosarcoma composed of atypical chondrocytes with hyaline cartilage matrix (left) and with myxoid matrix (right) (Hematoxylin and Eosin original magnification × 180).

Figure 3

Dedifferentiated chondrosarcoma is characterized by the coexistence of conventional chondrosarcoma (top; left side) and dedifferentiated components (top; right side). Dedifferentiated components are composed of atypical spindle cells in a storiform pattern, resembling MFH (bottom; left), or osteosarcoma with lace-like osteoid formation (bottom; right). Asterisk (*) shows artificial space. (Hematoxylin and Eosin original magnification top; × 50, bottom; × 180).

Figure 4

Leukocytosis appeared after the surgery. Elevated serum G-CSF level is shown (arrow). C-reactive protein is also increased.

Figure 5

Immunohistochemistry of G-CSF is absent in the conventional chondrosarcoma components (left), while is seen in the dedifferentiated components (right) (Immunohistochemistry original magnification × 250).