Purpose: Recent studies have shown increased levels of cyclooxygenase-2 (COX-2) in various human malignancies to include various bone and soft tissue tumors. However, little is known with regard to COX-2 expression patterns in chondroid tumors. Materi...
Purpose: Recent studies have shown increased levels of cyclooxygenase-2 (COX-2) in various human malignancies to include various bone and soft tissue tumors. However, little is known with regard to COX-2 expression patterns in chondroid tumors. Materials and Methods: Immunohistochemistry assays were performed for COX-2 in enchondromas (n=10), chondroblastomas (n=11), chondromyxoid fibromas (n=5), conventional chondrosarcomas (n=17), clear cell chondrosarcomas (n=7), and mesenchymal chondrosarcomas (n=6). Results: Among the benign chondroid tumors, chondroblastomas revealed characteristic strong positivity in 6 of 11 cases(54.5%). All enchondromas and chondromyxoid fibromas were negative except in one case. In conventional chondrosarcomas, three cases(17.6%) were strongly reactive with COX-2 and all positive cases represented grade III chondrosarcomas. Clear cell chondrosarcomas were found to be focally positive in two cases(28.5%), while all mesenchymal chondrosarcomas were negative. Conclusions: These findings suggest that COX-2 overexpression in conventional chondrosarcoma may represent an advanced histologic grade. Interestingly, expression of COX-2 in chondroblastomas could be an important factor for inducing peritumoral inflammatory changes in these specific tumors.