[Clinicopathologic and immunohistochemical study of 23 cases of mesenchymal chondrosarcoma].

OBJECTIVE

To study the clinicopathologic and immunohistochemical features of mesenchymal chondrosarcoma.

METHODS

The clinical and histologic features of 23 cases of mesenchymal chondrosarcoma were analyzed. Immunohistochemical study was also performed in 14 of the cases.

RESULTS

The age of patients ranged from 12 to 47 years. Fourteen of them occurred in males. Thirteen cases involved the bony skeleton and 5 cases affected the soft tissue. The patients presented with pain and/or swelling. Histologically, the tumor consisted of a mixture of undifferentiated small round cells and hyaline cartilage. Transition between the two components was demonstrated and growth plate-like cartilage was observed. Immunohistochemical study showed that the small round cells were positive for Sox9 (14/14), CD99 (12/14), vimentin (6/14), CD56 (4/14), CD57 (4/14), neuron-specific enolase (3/14) and desmin(1/14). They were negative for Coll-II, S-100 protein, epithelial membrane antigen, pan-cytokeratin, synaptophysin, chromogranin A, CD34 and c-erbB2.

CONCLUSIONS

Mesenchymal chondrosarcoma is a rare malignant tumor. Thorough histologic examination, when coupled with immunohistochemical findings, is helpful in arriving at a correct diagnosis.